What to Watch Monday: 90210 Ends, HIMYM and Castle Finales, Galaxy Quest Reunion and More

90210On TV this Monday: Castle, How I Met Your Mother and 2 Broke Girls end for the season; 90210‘s number is up; Hell’s Kitchen serves an extra helping and Warehouse 13 hosts an out-of-this-world reunion. Here are 10 programs to keep on your radar.

8 pm 90210 (The CW) | Two-hour series finale: After a retrospective featuring the show’s stars, the gang comes together when a traumatic event makes them realize the importance of their relationships. Prince Michael Jackson guest-stars, and the Goo Goo Dolls perform. (Get scoop.)

8 pm Hell’s Kitchen (Fox) | Tonight’s two-hour episode features two elimination rounds and a intimate dinner for distinguished members of the U.S. Army.

8 pm The Secret Life of the American Teenager (ABC Family) | Anne finds an ally in Kathleen, and Chloe meets someone from her past.

8 pm How I Met Your Mother (CBS) | Season finale: As everyone prepares to head out to Robin and Barney’s wedding, Ted invites Lily to see his fixer-upper, Marshall takes the baby on a last-minute trip to see his family and we may just meet the mother!… or we’ll just see her hidden behind another umbrella. (Watch a preview.) Casey Wilson (Happy Endings) and Keegan-Michael Key (Key and Peele) guest-star. (Yep, renewed.)

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9 pm Defiance (Syfy) | Irisa faces her past, and Nolan and Amanda face danger outside of town.

9 pm 2 Broke Girls (CBS) | Season finale: Max and Caroline offer to clean a previously hidden part of the diner… and in the process find something that could re-launch their cupcake business. Web Therapy‘s Tim Bagley and Jennifer Elise Cox guest-star. (Yep, renewed.)

9:30 pm Mike & Molly (CBS) | Molly’s so focused on directing a school recital that she doesn’t realize another teacher is hitting on her. Tim Conway (The Carol Burnett Show) and Jim Beaver (Supernatural, Deadwood) guest-star.

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10 pm Castle (ABC) | Season finale: An interview with a high-profile federal law-enforcement agency leads Kate to reconsider what she wants in her career – and in her relationship with Rick. (Watch a sneak preview, check out photos and find out why series creator Andrew Marlowe calls the hour “an emotional cliffhanger.”) Kyle Secor (Homicide: Life on the Street) guest-stars. Final Season 5 scooplet, per Matt Mitovich: The final scene runs about two minutes.

10 pm Revolution (NBC) | Boom-chicka-wow-wow? Militia drone strikes must be some kind of aphrodisiac, because the threat of imminent death heats up things for Miles and Nora and Charlie and Jason.

Warehouse 1310 pm Warehouse 13 (Syfy) | Tonight’s black-and-white homage to noir doubles as a Galaxy Quest reunion when Pete and Myka are pulled into a 1940s crime thriller featuring guest stars Enrico Colantoni (Veronica Mars) and Missi Pyle (Two and a Half Men).

10 pm Rectify (Sundance) | As Ted Jr. starts to question Daniel’s innocence, the ex-con begins to lose his grip on reality as he struggles with life on the outside.

Hit the comments with your must-see picks from tonight’s lineup!