"Murder. By all means, let's talk about murder," says Anthony Hopkins, and for the next two hours, he and other members of the cast of "Guilty Conscience," tonight's CBS movie, talk themselves silly. Richard Levinson and William Link, who have a fondness for writing clever mysteries when they aren't writing clarion calls to conscience, devised this caper about a lawyer who'd love like heck to snuff the wife.

He contemplates this at considerable length in the film, at 9 on Channel 9, and more than once fantasizes doing it, by hook, crook or basement steps. But then, being a lawyer, he also conjures an alter ego prosecutor and interrogates himself on the stand in imaginary trials that would follow the discovery of such a body as wifey's. Try as he may, he can't rig a loophole wide enough to jump through.

Lawyers practice the art of "bluffing," the attorney notes, and so do screen writers. "Guilty Conscience" might have made a trim and compact one-hour "Alfred Hitchcock Presents" a few years ago, maybe even a half-hour one, but there are no more anthologies, so it had to be bluffed up into a two-hour film. Director David Greene tries to hide the fact that there's a lot of stalling going on, giving such characters as the lawyer's mistress busy bits of business to fill up screen time, but it doesn't quite work. We keep thinking we're supposed to be having more fun than this, and we're right.

As the lawyer, Hopkins brandishes a mean lower lip that keeps threatening to go into a Charles Laughton droop. He's quite good as these obsessive blokes. Blythe Danner has an alluringly vulnerable dignity as the wife who sports a significant shiner; she carries herself like an empire about to topple. Swoosie Kurtz simply does too many Actor's Tricks in the misbegotten role of the mistress, coming on like a combination of Sally Field and Goldie Hawn on two bad days.

It would be a misdemeanor, if not a felony, to tip off too much of the plot, but it doesn't seem unfair to warn viewers that some of what seem like devilish twists turn out to be just hoaxy pranks by the filmmakers, along the lines of "oh ha ha, it was only a dream." But interest is sustained by Hopkins and Danner and their willingness to take the whole thing seriously, and by some semisnappy dialogue.

Wife: "Have you found a way yet?"

Husband: " 'A way'?"

Wife: "To kill me. Or is it still on the drawing board?"

Levinson and Link, who created "Columbo" and have a hand in "Murder, She Wrote," did a much better job of mystery game playing with "Rehearsal for Murder," starring Robert Preston, a couple of seasons ago. As a change of pace from the usual TV movie, "Guilty Conscience" is a welcome departure, but once having departed, it doesn't make quite the trip one is hoping for.