In Gotham, a Showtime movie that aired last summer, Virginia Madsen played a dead blond who comes back to spook her husband. In Third Degree Burn, another original movie, Madsen portrays another peroxided dish, who's out to frame Treat Williams for the murder of her wealthy old man. Too bad the material isn't as cool and well-shaped as Madsen's character, Anne Scholes, with whom Williams falls madly in love. Williams is Scott Weston, a divorced, Seattle-based private eye who always has his eye out for married women. A big-time executive hires this love-'em-and-leave-'em Lothario to follow his young, beautiful wife to an Arizona spa, and it's just a matter of time before Williams and Madsen find better ways than aerobics to burn calories. They go for the sexual gold, and although Madsen's fine body is kept pretty much under wraps, Williams's gets lots of exposure. The trouble with this mystery is it takes too long for anything mysterious to happen—the pace is slow, the dialogue soggy and the characters empty. At one point Madsen shares a confidence by saying, "Between you and I." Between you and me Third Degree Burn is not only ungrammatical, it's tepid.