Highlight of the night: a new episode of "The X-Files." Lowlight of the night: an old episode of "Step By Step."
* "The Adventures of Brisco County Jr." (8 p.m.-9 p.m., WBFF, Channel 45)-- The is a repeat of an episode in which horses of Brisco's wild, wild West are rivaled by a different type of horsepower: prototypes of motorcycles. The same concept was used earlier on TV in "Nichols," James Garner's playful but short-lived follow-up to "Maverick." Bruce Campbell stars. Fox repeat.
* "In the Line of Duty: Siege at Marion" (9 p.m.-11 p.m., WMAR, Channel 2)-- This 1992 made-for-TV movie, re-creating the FBI's confrontation with a well-armed religious group in Utah, is directed by one "Hill Street Blues" veteran (Charles Haid, who played Renko) and stars another (Dennis Franz). Two years later, it's also noteworthy, because its two most prominent players subsequently co-starred in rival, outstanding police dramas: Mr. Franz in ABC's "NYPD Blue," and Kyle Secor in NBC's "Homicide: Life on the Street." NBC repeat.
* "Step by Step" (9 p.m.-9:30 p.m., WJZ, Channel 13) -- About Suzanne Somers, who seems to be looking better, yet acting worse, these days: Not since Grimm's Fairy Tales have we witnessed such a frightening "Step" mother. ABC.
* "Burke's Law" (9 p.m.-10 p.m., WBAL, Channel 11) -- Get the deputy from "The Andy Griffith Show," one of the former "Hardy Boys," one of Bob Newhart's TV wives, and the host of "Fernwood 2-Night," and what have you got? Another wacky guest list on "Burke's Law." Don Knotts, Parker Stevenson, Mary Frann and Martin Mull appear on tonight's show. CBS.
* "The X-Files" (9 p.m.-10 p.m., WBFF, Channel 45)-- The FBI agents on this paranormal program visit the Pacific Northwest -- "Twin Peaks" country -- to investigate a swarm of supposedly extinct insects. Beware: The mosquitoes are not what they seem. Fox.
* "Sister, Sister" (9:30 p.m.-10 p.m., WJZ, Channel 13) -- When a tough test comes up at school, the smarter twin subs for the other. Oh, brother, brother. ABC.
* "Picket Fences" (10 p.m.-11 p.m., WBAL, Channel 11) -- Chris Sarandon, who brought warmth to a potentially thankless role as the ex-husband on last Sunday's "David's Mother," brings his energies to another supporting role and does very well. This time appears with guest star Marlee Matlin in a repeat about a strange group of bank robbers. CBS repeat.
* MIA: The Long Journey Home" (9 p.m.-10 p.m., A&E) -- Host Bill Kurtis does legwork this week, returning to Vietnam for an "Investigative Reports" about the search for American MIAs.