"Come, Watson, come! The game's afoot!"

This cry, echoing from Arthur Conan Doyle's Edwardian London, heralds the coming of seven "Adventures of Sherlock Holmes" on PBS. The first two are served up on silver fund-raising platters tonight on Channel 26: "A Scandal in Bohemia" and "The Speckled Band."

Waiting for the fundraisers, buffs will need appropriate pots of tea to sustain them, if not (illegally) Holmes' own 7 percent solution or (unhealthfully) a pipeful of tobacco or (noisily) violin accompaniment. Approximate times are 9 to 10:15 and 10:15 to 11:15, including a pledge break.

The first tells the remarkable tale of the royal lover, an early victim of the blackmailing photograph. The heroine is the magnificent Irene Adler (Gayle Hunnicutt) -- "To Sherlock Holmes she is always the woman."

The second is the curious case of "The Speckled Band," with elements left over from mystery novelist Wilkie Collins -- gypsies, military men from India and brave but endangered maidens.

Granada Television, the same English company that produced "The Jewel in the Crown," treats Holmes, a national hero, even more respectfully than did Mrs. Hudson, his admirable landlady. It pays great scholarly attention to niceties of dress -- top hats for town, not the deerstalker cap beloved of other Holmes pretenders. The dialogue sounds properly prissy. The Baker Street Irregulars and other Doyle groupies will need to put magnifying glasses to the sacred canon to catch inaccurate flakes of ash or bits of mud.

Scenes of London -- including the meticulously recreated Baker Street, where Holmes lived at his 221-B flat -- recall Doyle's description: ". . . that great cesspool into which all the loungers of the Empire are irresistibly drained."

The unnamed (or set designer's illusion) country house which is the villainous decayed ancient seat of evil in "The Speckled Band" echoes another Doyle view: "The lowest and vilest alleys of London do not present a more dreadful record of sin than does the smiling and beautiful countryside."

Though, like Watson, we know Holmes' methods, the plots are still ingenious and perplexing, even if you read Holmes through regularly, as the faithful do, and remember the tricks and terms of the puzzle. It's rather like hearing an old family story, told again by a younger member. We all know how it's going to come out but it's a pleasure to hear the new performer.

A hint for those who have never read the holy text -- follow the Holmesian adage: "When you have eliminated the impossible, whatever remains, however improbable, must be the truth."

There are those of us who would watch a Sherlock Holmes program if the master were played by an black cat (which Jeremy Brett closely resembles). But Brett, who was also responsible for the cold-blooded portrayal of Max de Winter in PBS's "Rebecca," is a rather bloodless Sherlock Holmes. And David Burke as Dr. Watson tries so hard not to be a buffoon that he's just dull. Those brought up on Basil Rathbone and Nigel Bruce may find this twosome disappointing.

But this is carping. With all the stupid car chases and knock-down-and-drag-'em-outs on television, the cerebral Mystery is a moonstone of great value. Most recently, the Agatha Christie "Parker Pym" series proved again that Christie seen is far superior to Christie read. Now why not bring back "Murder Most English" to finish the great Dorothy Sayers cycle? The first, though the best of all the television mysteries, never included the later Peter Wimsey mysteries that costar Harriet Vane. And what about stories by contemporary masters -- Ross Thomas and Charles McCarry?

"Excellent!" I cried.

"Elementary," said he.