IF YOU'VE SECRETLY LONGED to outwit Hercule Poirot by solving a dastardly murder; to zing one-liners like Walter Matthau in "Plaza Suite"; hobnob like the English gentry from hunt breakfast to black-tie ball; curl by a country fire, stalwart as an Appalachian mountaineer; or judge antiques like an auction-house aficionado, now's your chance.

Adventure weekends are here. These inns and bed-and-breakfast homes in Pennsylvania, Maryland and Virginia, allow you to play roles while creatively answering that getaway conundrum, "But what will we do there all weekend?"

MURDER AND MAYHEM

HARRY PACKER MANSION

Jim Thorpe, Pennsylvania

Sherlock Holmes would have felt right at home in this elaborate Poconos hilltop manse, built in 1874 by railroad magnate Asa Packer as a wedding present for his son Harry. With intricate hand-painted ceilings and elaborate double parlors adorned with settees, marble top tables, oriental rugs, gilt mirrors and carved mantles, and gently lit as if with a gas-lamp glow, the house exudes a fine Victorian elan: ornate, fussy and mysterious.

This is the perfect place to murder a relative, and every weekend from September to May (except for Christmas) Patricia and Bob Handwerk help you do just that. Unlike many other mystery weekends, here you not only play detective, you also enact the drama, loosely based on a real-life Packer family intrigue that rivals a month of "Dallas" deceits. Last year's plot involved illegitimate heirs, fake pregnancies, secret affairs and, of course, a murder. "A $50 million inheritance at stake doesn't bring out the best in the Packer characters," says Patricia, who assigns guests roles Friday night after a private half-hour talk.

"I usually pick the shy ones to play the real sleazy characters. These people come alive," says Patricia. "One weekend when I picked a very prim and quiet woman to play Mary, the whole group was disappointed, but this woman became Mary. She was rude and obnoxious. On Sunday she thanked me profusely, told me it made her a whole different person."

But you don't have to worry about memorizing scripts. The Handwerks guide you with character descriptions, motivation and a series of clue packets, different for each guest. By revealing your clues, cued by the Handwerks, and by reacting to the other characters, whether it's Annie, a Bette Midler floozie, or Piersall, the steady butler, or crazy Dr. Irwin (known for his uranium experiments), the mystery is revealed. On Saturday afternoons, there's time to explore Jim Thorpe, a funky Victorian town, just slightly gentrified, that sports craft galleries in the old stone rowhouses Packer built for his workers, a turreted train station and spectacular views. In season, enjoy mountains dappled with fall hues, downhill skiing or cross-country skiing on the switchback trail from the lake to the inn.

How Bob, an architect, and Patricia, a former marketing director for a Fortune 500 company, came to leave Philadelphia fast-track lives to direct murder in the mountains is itself a series of unlikely happenstances.

"We were looking for a weekend getaway house, an A-frame in the country," says Bob. "But we ended up with this Victorian mansion instead." After a stop to tour the Asa Packer mansion next door, the Handwerks took shelter from a sudden rainstorm on the Harry Packer house's arched verandah.

"I looked down and saw a 'for sale' sign in the weeds," says Patricia. Fascinated by the architecture, we called the realtor who didn't want to show us the house because everybody had been calling just to tour it. We finally found another realtor to show it to us. The house was for sale because of a messy divorce, and the lawyers hadn't been paid for years."

Awed by the massive carved staircase, the mantles, paneling, and especially the three stained-glass dining room windows, "Morning," "Noon" and "Night," which the Handwerks later learned were Tiffany originals, they contemplated purchasing the mansion, which had snowdrifts piled high in the second floor bedrooms, gaping holes in the roof, and a very iffy heating system. "We thought of the lowest possible, ridiculous offer, then cut that in half, never thinking they'd accept," says Bob. "When they did," says Patricia, "I got Bob drunk and convinced him to sign an agreement for sale." They settled, by coincidence, on February 1, 1984, the 100th anniversary of Harry's death.

Now the Handwerks are fulltime innkeepers, and Harry's house fills with weekend adventurers enjoying mystery tours, nearby whitewater rafting, Victorian balls and private trysts. But murder is most popular; these weekends often book a year in advance.

"We don't kill our guests," says Pat, "but you might be the murderer. People love that. One woman was so excited she phoned her kids and said 'Mommy was a murderer.' When she came home, they had a noose hanging on the front porch." With its high Victorian glitter and the chance to play villain, tycoon, hussy and detective, the Packer Mansion in the Poconos offers a weekend of mystery and pure fun.

THE HARRY PACKER MANSION --

Packer Hill, Jim Thorpe, PA 18229. 717/325-8566. Seven guest rooms share three baths $65-$75 a night, including full breakfast. One suite with private bath, $110 a night. Mystery Weekends September to May; midweek anytime. $275 per couple; suite, $345; includes lodging Friday and Saturday, breakfast Saturday and Sunday, dinner Saturday night at the mansion. All inn guests participate in the murder. Romance package: weekends May to November, or midweek anytime, two nights lodging in the suite, candelight dinner in town, breakfast in bed, fresh flowers and a small gift, $280 per couple. Adventure Package: May-November, two nights lodging, two breakfasts, picnic lunch, and a whitewater raft trip down the Lehigh River, $240 per couple, suite $310. Victorian Balls: held festival weekends in May, August and December. Waltz to string ensembles in your Victorian fancy dress, and enjoy a buffet dinner, accompanied by harp music. $35 per person, plus regular lodging rates. Take I-95 north to I-695 to I-83 north to I-81 north. Exit Rte. 54 east, which becomes 93 to Jim Thorpe. 220 miles, about 4 1/2 hours.

SOCIETY HILL HOTELS Baltimore Government House; West Biddle; Hopkins

Baltimore, from the business district to the galleries to the inner harbor, sets the scene for this murder weekend as you follow a trail of clues planted all over town by David Landow's "Murder to Go." At Baltimore's Society Hill Hotels -- Government House, West Biddle and Hopkins -- one weekend a year all 100 guests turn amateur detective, taking trollies to famed city sites where the plot, propelled by 10 actors posing as guests or waiters or even innkeepers unfolds.

"The Magic of Murder," this year's mystery tour, begins with a buffet in the VIP parlors and dining rooms of Government House, an elegantly restored, turreted and gabled 1889 city house, managed by Society Hill, but usually reserved for Baltimore's visiting dignitaries. More clues appear at an evening seance at International House, complete with psychics and magicians. On Saturday there's mayhem in the courtyard of the Tindeco, an historic waterfront apartment building, a revealed fakery at the Walters Art Gallery, a stealthy visit to Poe's grave, perhaps a streetside duel, and then deceit during dinner at Haussners.

"What's different about this mystery weekend is that it's physically active," says hotel co-owner Judith Campbell. "We transport guests to scenes all over town."

And with the actors unidentified, it's hard to know a clue from a curiosity. "It's wild," says Campbell. "Last year, you'd come back to the hotel, hear a fight on the stairs, and someone screaming 'I'm getting a divorce.' You didn't know if that was a personal problem or part of the plot, because the murderer could be the guest in the room next to you."

Most of the rooms at these three city inns offer a pleasing mixture of updated Victoriana. The turn-of-the century iron and brass, oak beds or the contemporary brass headboards look inviting with their draped canopies that coordinate with floral wallpapers and dark green and mauve walls. But many rooms are small, especially at West Biddle, so try for a King room, or a Queen with a sitting area.

Society Hill West Biddle, on a corner behind the Meyerhoff Symphony and across from a Buick dealership, has no elevator and no parlor, but with Society Hill Restaurant, noted for its Maryland crabcakes and jazz piano bar, in the basement, this hotel could get noisy. Three blocks away and a bit more upscale with an elevator, parlor and bigger and brighter rooms, Society Hill Government House comprises two turn-of-the-century buildings adjacent to Baltimore's Government House. Favorite rooms here include the tower rooms. Though not large, their semicircular array of windows affords an airy room with a splendid view. Or try No. 205, a good-size charmer with its original ceiling mouldings, a settee and peach walls. Art Deco lovers will enjoy pondering clues in Society Hill Hopkins' suites with black lacquer headboards touched with purple and fuschia, or in the '30s suite of waiting-room vinyl couches and chrome chairs.

The Society Hill Hotels offer small-inn intimacy in the heart of the city, and during murder weekend, the added excitement of mystery theater. Finger the murderer and the motive first, and win a prize: a free murder mystery weekend next year.

SOCIETY HILL HOTELS --

58 West Biddle, Baltimore MD 21201. 301/837-3630. 15 rooms with private bath. Society Hill Government House, 1125 N. Calvert St. Baltimore 21205. 301/752-7722. 18 rooms with private bath. At these two hotels: single $65; double, queen $85; king $105, includes continental breakfast in room. Society Hill Hopkins, 3404 St. Paul Street, Baltimore MD 21218. 301/235-8600. 26 rooms, including 10 suites. Single $85; two-room suite $105; suite with kitchenette, $125. Mystery Weekend: October 9 to 11, $295 single, $500 double; includes two nights lodging, dinner buffet Friday night in the Victorian splendor of Government House; two breakfasts; Saturday night dinner at Haussners; mystery tour transportation by trolley.

IN PENNSYLVANIA'S BRANDYWINE VALLEY

murder is also afoot. For country house mysteries January 22-24, and January 29-31, contact Janice Archbold, Guesthouses and Boxwood Tours, RD 9, West Chester PA 19380. 215/692-4575 noon to 4. Guests, who portray characters while solving the mystery, are told to bring costumes appropriate to the role. While prices aren't firm yet, costs should range about $545 to $620 per person, including two nights lodging, two dinners and two breakfasts.

COUNTRY HOUSE WEEKENDS

GUESTHOUSES AND BOXWOOD TOURS

West Chester, Pennsylvania

If your fantasy getaway involves estate homes, manicured gardens, coffee and croissants in bed brought on silver platters by attentive servants, horses, hounds and hobnobbing at formal dinner parties -- a la Masterpiece Theatre -- then Janice Archbold of Great Country House Weekends is your fairy godmother. Her adventure weekends drop you into Brandywine society to see such tony staples as the blessing of the hounds at the start of the Radnor Hunt, the Steeplechase at Chesterlands, where the members of the U.S. Olympic team compete, and sculling on the Schuylkill, complete with champagne brunches of omelettes with caviar, tailgate luncheons served by liveried servants bearing fine china arrayed with brie, venison, quail eggs and smoked pheasant.

Says Archbold: "Part of the fantasy for people is a nostalgia for the kind of thing they never had."

But now you can. This is no mere nose-pressed-against-the-glass view. With Archbold waving her wand, you dine with the hunt riders and race crews, and dance at Saturday night's black tie ball with the local gentry. "If I wanted to go to the races at Saratoga," says Archbold, "I could see them, come back and stay at the Howard Johnson's, but I wouldn't have met anybody who rides there. I really wouldn't have had a Saratoga experience."

Archbold delivers the quintessential Brandywine. Guests, who mingle at events and dine together, stay at one of three country manor homes: Hamorton, an elegant 34-room, 1850 estate on 35 acres of lawns and woods; Sugarbridge, a charming 12-room 18th-century Georgian house, graced with Federal antiques and surrounded by 50 acres of cornfields; and Cornerstone, an 18th-century fieldstone farmhouse on 20 acres, decorated with spool beds, quilts, Federal pieces, but replete with such modern comforts as a pool and hot tub.

"We're trying to recreate an era of elegance, with butlers and black-tie dinners. These are Edwardian house parties with total elegance designed to make guestsfeel privileged and pampered. These are parties like the Mellons and du Ponts give, but they're given by wonderful Brandywine landowners," says Archbold.

After Linda Chamberlin, a DuPont marketing manager, who rides with the hunt, hosted "The All American Fourth of July" at Cornerstone, she was hooked.

"It was pure pleasure. As a host, all I had to do was get the ball rolling. Janice sends in her whole crew, and I can enjoy the people. By the end of the weekend all these strangers were confiding and loving one another like family."

That was Chamberlin's wish come true. "I come from a small family. This was part of my fantasy of what it would be like to come from a big family, and they all came here for some great celebration. It was like a dream." But one with perfect timing. "Like my German grandmother used to say, 'Fish and company stink after three days.' On Sunday everybody leaves and the clean-up crew comes."

With Great Country House Weekends, pack your glass slippers and tux for a getaway whirl with the Brandywine gentry. When Sunday midnight turns your hunting steed into the Metro that stops at Federal Triangle, you'll still remember the sound of clinking crystal and the way the starlight touched the boxwood drives.

GREAT COUNTRY HOUSE WEEKENDS --

Janice Archbold, Guesthouses and Boxwood Tours, RD 9, West Chester PA 19380. 215/692-4575 (noon to 4). Steeplechase: Chesterlands, September 25-27; Radnor, October 16-18; Unionville-Pennsylvania Hunt Cup, November 6-8; $519 per person with shared bath, $539 per person with adjoining bath; $559 per person, for a suite. Sculling on the Schuylkill, includes a visit to Philadelphia Museum of Art to see Thomas Eakins' portrayal of 19th-century scullers, October 23-25; $513 per person for shared bath, $533 for adjoining bath, $533 for a suite. Foxes and Hounds, November 13-15, November 20-22 and December 4-6; $522 per person with shared bath, $542 for adjoining bath; $562 for a suite. Candlelight Christmas, includes walking tour of Historic West Chester, December 11-13; historic New Castle, December 18-20, $545 per person with shared bath, $565 for adjoining bath, $585 for a suite. The Brandywine Valley is approximately 2 1/2 hours from D.C. via I-95 north to Rte. 202 north to U.S. 1 north.

DEARMONT HALL THEMED WEEKENDS

White Post, Virginia

There's mountain magic at Dearmont Hall, a gracious 1840 country farmhouse on 15 acres in the Shenandoah Valley. Sit in the wicker rockers on one of the double porches, a welcoming glass of wine in your hand, and catch the sunset over the dappled Blue Ridge Mountains. These hills hold treasures of crafts, history and tales. Revolutionary War hero Lawrence Butler, buried on the hillside, came home here to farm nearly 400 acres, and during the Civil War, grande dame Lucy Dearmont hid Confederate soldiers in the center-hall staircase.

Now innkeepers Linda Peek, press secretary to Senate Majority Leader Robert Byrd, and her mother Bobbye Peek, continue the tradition of Dearmont Hall as a gentle homecoming from politics and city concerns. During "Ozark Collection Weekend," curl by the fire, listen to mountain folk tales and find a new fantasy hero for power couples beleaguered by work monsters: Appalachian Jack.

"He's the Jack in the beanstalk. He's a trickster, hunter, but also a fool who succeeds," says West Virginia storyteller Marie McCray. "That's why he's popular. When the giants come to kill him, he'll devise down-home crazy things. He'll whack a giant with a washtub, or have them kill each other with trees. He does the impossible."

"Storytelling," says McCray, "touches the heart instead of the intellect." So do the dulcimer music, provided by the Bluemont Concert Series, and the fine Arkansas and Tennessee needlepoints, wooden children's toys and wall hangings, displayed just in time for Christmas shopping. During "Antiquing Weekend" here January 22-23, take to the hills of Clarke County in search of centuries-old treasure. After lectures by local dealers on how to tell a true 19th-century pine kitchen table from a roadside knockdown, or a 19th-century country quilt from a modern copy, take a guided tour of the local shops featuring quilts, country furniture and some formal English pieces.

Afterwards, relax in one of three cheerful guest rooms, decorated with antiques and country comforts, including the Lucy Dearmont room, a favorite, decorated with Peek's great-grandmother's white iron bed graced by a lone star quilt. Each guest room sports a Peek must: "Every room has a rocker and a bookcase. I think that's imperative to enjoy a country week-end," says Linda Peek. Grab a spy novel, country diary, gothic romance or country cookbook, along with another Peek must: Bobbye Peek's pound cake. Then read in your room, or in the parlor, adorned with a Samurai sword, a Budapest folk painting and Bobbye Peek's collection of antique fans. Dearmont, eclectic and sophisticated, is country comfortable, still providing the warm mountain homecoming that war-weary Butler sought.

"Here you bring things down to a personal level," says Linda Peek. "You feed the ducks, you play with the dog, take a walk by the creek. It's a terrific way to leave the city behind."

DEARMONT HALL --

Route 1, Box 158A, White Post, VA 22663. Bobbye and Linda Peek. 703/837-1397. Three guest rooms, two with private bath. Room with private jacuzzi, $95; private bath, $90; shared bath, $75, includes full country breakfast, afternoon tea, wine and cheese. Storytelling Weekends: $110 per person per weekend, double occupancy, includes two wine and cheese receptions, two nights lodging, two country breakfasts, Saturday night storytelling, coffee and dessert. "Country Halloween," ghost stories in front of the fire, masks and music, October 30-31. "Ozark Collection Weekend," mountain stories, crafts and music, November 13-14. "Virginia History Weekend" Friday night special guest Tim Hackler, director of the American History Media Center in Washington, to discuss tales of Thomas Jefferson and Alexander Hamilton, February 26-27. "Irish History Weekend," a little blarney fireside with Irish stories and music, March 16-18. Antiquing Seminar and Shop Tour, January 22-23. $110 per person per weekend, double occupancy, includes two wine and cheese receptions, two nights lodging, two country breakfasts, antique lectures and tour. Valentine Lover's Weekend, February 12-13, includes breakfast in bed.

THE RIVER HOUSE

Boyce, Virginia

For more tales, try The River House's "Enter Laughing -- A Weekend in the Country," where Cornelia Niemann, a veteran actor and director who calls herself "a woman of an uncertain age," leads you through the best of comic scenes by such laughmasters as Kaufman and Hart and Neil Simon. This is for closet thespians, comedy lovers and anyone who's ever longed to deadpan an audience to delirium. It's also theatre without the stage fright, or hard work. "It's all non-threatening. We'll be sitting on the floor reading scripts with the lights low," says Neimann. And it won't matter if you're not right for the part. "Young girls can play old people, and old people ingenues."

After all, this is your comedy fantasy weekend, and River House, a stone house on 15 acres on the Shenandoah River (the house's oldest section dates to 1780), provides a cozy setting with its mix of antiques and comfortable pieces in rooms mellowed with open hearth fireplaces, pine flooring, and 18th-century Virginia stone walls. Favorites include the Hearth Room, with its five-foot stone fireplace, and the Master Bedroom, with its antique double bed and sitting area. "We all love these special comedy scenes, so why not do them with everyone else? There's not enough laughter around these days," says Neimann. But you can find a weekend full at The River House.

THE RIVER HOUSE --

Boyce VA 22620. 703/837-1476. Five guest rooms, including one suite, four with private bath. $45-$70 for one night, per double room; $70-$120 for two nights. Enter Laughing Weekends: November 20-22, January 29-31, March 18-20; $95 per person, double occupancy. Surcharge of $10 for the Hearth Room and the Master Bedroom; 10 percent discount for entire series paid in advance. Includes two wine and cheese parties, two nights lodging, two country breakfasts and catered dinner Saturday night.