In spring, the Nationals sang their songs of innocence. In a new town with a fresh start, they were a band of brothers. Called "misfits and outcasts" by their manager, they stormed to a 50-31 record to stun baseball. But innocence never lasts. In biblical terms, you bite the apple and are given the dangerous gift of knowledge. You see your nakedness. In baseball, you are said to "take the apple" -- an expression for choking under the pressure of expectations. But biting the apple and taking the apple can be similar. You gain in knowledge, but lose in innocence. In baseball, you see yourself and your team complete, with all its flaws of talent and temperament. For two months, the Nats endured a daily tutorial in human frailty. After winning 12 straight one-run games, a major league record, they lost 13 straight one-run games, a major league record. Symbolic enough?

Now in September, knowing themselves better, although liking each other distinctly less, the Nats now sing a different tune. With nods to William Blake, they're learning songs of experience, lessons that come after the fall from a brief state of grace. For almost a month, the Nats have been stabilizing their play (12-11), confronting their internal issues, trying to play with a fraction of their inspiration in June, despite all the feuds and fractures that gradually became public since then.

In the last two days, with consecutive "must wins" over the wild card-leading Phillies -- 5-4 in 12 innings, then 6-1 yesterday at RFK -- the Nats find themselves back in the thick of the wild-card mix amid giddy postseason permutations. Outside the Nats' clubhouse on a grease board four words were written large: "The Fun Has Begun."

Just as it seemed likely to die. If the Nats had lost these last two games, they'd be six games out in the wild card and you'd be reading a baseball obit right now. Instead, with 16 more home games, a trio of top starters and the deepest bullpen in the league, the Nats are just one hot streak away from returning to fantasyland. Just as important as their revival in the standings, the Nats realize that they are no more internally divided, no more stressed and hissy, than their wild-card rivals.

While innocence daydreams, experience observes. When the Nats measure themselves against their wild-card foes, they see the same flaws in the Phillies, Mets, Astros and Marlins that they see in their own mirrors. Is rookie Met manager Willie Randolph up to the task of handling a rich Big Apple contender? Is Carlos Beltran the big-buck bust of the season? How bad is Roger Clemens's hamstring injury in Houston? Did Florida Manager Jack McKeon "lose the team" months ago? Or do the Marlins simply have chemistry so bad they make the Nats look like a Brady Bunch remake? And count on Philly to gnaw on its Phils.

Ironically, in every other wild-card city it's the Nationals who are used to illustrate how abysmally the local team is underachieving relative to its fancy payroll. What's the matter, you guys can't even beat the ownerless Expo-budget Nats?

"You see everybody going through the same kind of situations," said Carlos Baerga. No sooner than he says it, the Nats, on their clubhouse TV, see the Reds beat the Braves with a grand slam home run. "That's what I'm talkin' about," crows Baerga.

"There isn't any team that doesn't have turmoil and adversity," said Preston Wilson, who was initially criticized as General Manager Jim Bowden's folly, but is now contributing nicely, including a Section 447 upper deck three-run homer yesterday. "Every year, the teams that win talk about all the adversity they went through. That's because it's true.

"Of course, the last-place team went through adversity, too."

The open question about the Nationals now is whether, in the clear light of their on-field fallibility, their constant nagging injuries and their clubhouse squabbles, they can play determined baseball for one more extremely arduous month.

"In May, if you had told me that there would be a 180-degree reversal [in attitude] in this locker room, I would have looked you in the face and called you a liar," one of the Nats' stars said yesterday. "It's been amazing to watch [the deterioration]. I wouldn't have believed it. But, despite that, we can still win."

Or, perhaps, because of it. The Nats are now just another fascinating unhappy family -- like the rest of us. If they somehow end up in the playoffs, or even take the race to the last-week wire, they didn't do it by some one-time-only first-year-in-Washington summer-of-love fluke. They did it after everybody saw the worst in each other, the product of a slump that lasted one-third of a season -- 54 games (19-35). There's friction everywhere. Not beyond the big league norm. But plenty.

You don't have to seek out in-house sniping -- at the 70-year-old Frank Robinson's work ethic or Bowden's trades and call-ups or Tony Tavares's budget restrictions. It walks up to you and starts the discussion. Frank doesn't know the most basic stats. Bowden wants to shove rookies down Frank's throat in a playoff race. Tavares wants to show the next owner, who'll have to pick a team president, how well he saves a buck. As for the ex-Expo contingent, proud of its head-in-the-game style and reluctance to use injuries as an excuse, it doesn't always appreciate the distracted diva-inclined tendencies of some New Nats.

Who'd want to miss an installment of this stuff? On Friday (a.k.a. "The Day the Music Died"), Robinson played tough-love father and shut down all pregame and postgame clubhouse music, card playing and video viewing. Too many mental mistakes over too many weeks, punctuated by too much post-defeat laughter, caused the clampdown. After Saturday night's cathartic win -- when a game-winning bloop single erased the memory of back-to-back save-blowing home runs off Chad Cordero -- some brave Nat tested the length of Robinson's no-fun policy by turning on the radio. Frank snapped it back off.

After yesterday's victory, nobody tried the radio trick. Luckily, every National is still allowed to breathe, drink tap water and speak, although the sign "Home Clubhouse" may soon be replaced with "Home Library. Quiet, Please."

Don't expect the soap operas to stop. The days of innocence are over. Now it's the hard wisdom of experience that counts.

"From now on, 'trying hard' isn't enough. Anybody can try. My mama can try," said veteran Vinny Castilla. "This time of year, you gotta win."