TONIGHT'S MUST-SEE:

"Southland" debut, 9 p.m., NBC.

This cop show is a strange choice to inherit the "ER" slot.

Yes, it's from the same producer (John Wells); its central character (played by Ben McKenzie of "The O.C.") seems like Dr. John Carter reborn. But "ER" brought hope and idealism; this "Southland" debut is drenched in despair ... plus the distraction of too-jerky camera movement.

Still, there are spurts of great dialog, often emerging from training officer John Cooper (Michael Cutlitz). A hard-core cop with a gift for lyrical language, he offers hints that "Southland" might get better.

TONIGHT'S MIGHT-SEE:

"Harper's Island" debut, 9:01 p.m., CBS.

Abby Mills (Elaine Cassidy) loved growing up on this island, until her mother and five others were killed. Now she's returning for the first time in seven years.

She's there to see her friend (Christopher Gorham) marry an heiress (Katie Cassidy). She soon finds a schism between classes; she also finds new murders, one per episode.

This is an ongoing mystery, moving toward a July 2 conclusion. It sometimes plays like bad soap opera, but the Abby character has depth and empathy.

And no, the Cassidys aren't related. Elaine is from Ireland, Katie (David Cassidy's daughter) is from California.

TONIGHT'S ALTERNATIVES:

-- "The Office," 7 and 8 p.m., NBC. Both episodes involve Jim's shaky relationship with Charles, the new supervisor. In the first, they're in a soccer game in the parking lot. In the second, Charles tells Jim to prepare a "rundown"; Jim, alas, has no idea what that is.

-- "CSI: Crime Scene Investigation," 8 p.m., CBS. When a skydiver dies, Catherine finds a possible link to a double murder.

-- "Grey's Anatomy," 8 p.m., ABC. In a rerun, Cristina gets to try solo surgery. Also, Mark's difficult operation impresses Lexie.

-- "30 Rock," 8:30 p.m., NBC. Budget cuts mean Jack is supposed to trim staff and Kenneth has extra responsibilities. People become suspicious of Kenneth and hunt for some dark secret.