CHARLES AND DIANA went home. Smiling Mike Gorbachev went home. The fat lady has sung in the House Ways and Means Committee. So, what next to jump-start our imagination here in the inside-the-Beltway sandbox?

Why, it's Washington's newest dinner party game called, "Which one of us is the spy?" Cloak-and-dagger paranoia sweeps the city and we seem to be about ready for a sight- seeing spy tour of the Nation's Capital -- "On your right is the Au Pied de Cochon where Vitaly Yurchenko gave the slip to this CIA keepers. He soon defected and the CIA had to take the lie detectors back to Radio Shack.

"See that pizza parlor? There's a plaque in there next to the table where last year some agents found microfilm under the pepperoni.

"Over there off Dupont Circle is Jonathan Pollard's apartment. He's accused of spying for Israel. He must have been an apprentice where they start you off spying on allies. Later on, it's the big leagues -- Syria."

According to the data on recently indicted spies, the traitor in your midst at your dinner party could be the one whose conversation is filled with patriotic fervor -- as in "No wine for me, thanks, until the Russians are out of Afghanistan." It's not as if he will be so obvious as to turn to the host and say, "If I get up and leave the party early, will you shoot me?"

But, as you scrutinize your fellow guests at the table, be alert for the flake, the one with the phony French Legion of Honor pinned to his lime- green polyester leisure suit.

His beeper will go off and he'll say something like, "I told Bill Casey not to bother me while I'm having dinner."

His business card may indicate that he's a part-time international consultant/private detective/toaster repair man and dance instructor.

This man fits the composite of all defendants in this year's spy cases, so you should call the FBI, the CIA or the National Security Agency first thing the next morning. But no matter who you call, don't be surprised if the man himself answers the phone.