I never thought I would be happy to see the return of “Big Brother” (7 p.m., CBS), but after “The Cut” (which moves to Wednesdays to complete its run in well-deserved obscurity) anything is a relief.

CBS morning-show host Julie Chen returns to emcee the claustrophobic shenanigans on this, the sixth season of “Big Brother.” Any rumors that she considers this duty beneath her dignity as a “journalist” are decidedly untrue.

This season, the “Big Brother” housemates move into a brand-new house. And, boy howdy, big changes are in store. There are now – drum roll please – two stories to the “Big Brother” house. This may not seem like much, but to the producers and editors who splice together the show for our viewing pleasure, the very fact that the contestants have to walk up and down stairs adds whole new vistas of time-wasting padding to the proceedings. In past “Big Brother” competitions, we spent countless moments watching players walk in and then walk out of the video voting booth. It’s idle moments like these that add up to a 60-minute show, a two-month season and continuous live Internet feed.

And the excitement doesn’t end with mere stair climbing – not by a long shot. This season, the 14 contestants get to share a backyard Jacuzzi. Let’s hope the makers of “The Real World” aren’t watching. Or, if they are, let’s hope MTV’s lawyers haven’t gotten to the word “plagiarism” in their MTV law books. “The Real World” always has a Jacuzzi, even in Paris. And rumor has it that the citizens of Paris had never seen an outdoor Jacuzzi until “The Real World” moved in.

Tonight’s other highlights

¢ Christian Bale and Matthew McConaughey star in the 2002 dragon-slaying fantasy “Reign of Fire” (7 p.m., ABC).

¢ On back-to-back episodes of “Will & Grace” (NBC), daddy issues (8 p.m.), Molly Shannon (8:30 p.m.).

¢ Mail-order brides, signed, sealed and delivered to their doom on “CSI” (8 p.m., CBS).

¢ Things get steamy on “The O.C.” (8 p.m., Fox).

¢ Internet creeps kidnap an heiress on “Without a Trace” (9 p.m., CBS).

¢ Weaver’s mother and child reunion on “ER” (9 p.m., NBC).