TONIGHT'S MUST-SEE

"Lonesome Dove" (1989) part one, 8 p.m., Ion (formerly PAX); continues for three more Saturdays. One of the great TV miniseries returns, nudging Ion in a new direction. The network began in 1998 as Pax, with feel-good, family-friendly shows. Later, it switched to a bland name (Ion) and a blank identity. Beginning now, however, producer Robert Halmi's company will program Ion on Fridays through Sundays. It's planning new movies, but starts with its best rerun. Beautifully adapted from the Larry McMurtry book, "Lonesome Dove" captures the quiet cadence of the cowboy world. Simon Wincer directed a superb cast, led by Robert Duvall and Tommy Lee Jones.

"Jesse Stone: Night Passage" (2006), 10:30 p.m., CBS. This is the second Stone film, but the best one to start with. It's a prequel that catches Jesse (Tom Selleck) starting work as a small-town police chief. He drinks a lot, frets a lot; he's also a good and honest cop.

OF NOTE

"There's Something About Mary" (3 p.m.) and "Dodgeball: A True Underdog Story" (5:30 p.m.), FX. Ben Stiller stars in two broad comedies. The first has Cameron Diaz as his long-ago love; the second is a takeoff on all those against-the-odds sports movies.

"A Prairie Home Companion" (2006), 5 p.m., HBO. The final film by the late Robert Altman is a quiet delight. The setting is a fictional version of the "Prairie Home Companion" radio show. Garrison Keillor plays himself, with Kevin Kline as Guy Noir, now working security. There are great supporting bits from Meryl Streep, Lily Tomlin, Woody Harrelson and Lindsay Lohan.

"America's Got Talent," 7 p.m., NBC. Here's a quick rerun of the New York auditions.

"The Haunted Mansion" (2003), 7 p.m., ABC. Eddie Murphy brings his family to a creepy old house, where — no surprise here — creepy things happen. It's a comedy.

"Medium," 9 p.m., NBC. In a rerun, Allison is dismayed that the ghost of her ex-boyfriend won't go away; he's played by Thomas Jane, the real-life husband of series star Patricia Arquette. Meanwhile, Bridgette dreams of clues; since she's a youngster, her dream is in cartoon form.

"Saturday Night Live," 10:30 p.m., NBC. Matthew Fox hosts this rerun, with music by Tenacious D, the band created by Jack Black and Kyle Gass.