Nature: Ocean Giants (8pm, UNC-TV) - A three-hour special on the underwater world of whales and dolphins. Included, the human-like qualities of the animals and their reliance on sound underwater.
American Idol (8pm, Fox) - Contestants have one last chance to win over the judges before the first group of semifinalists are revealed.
Raising Renee (8pm, HBO) - NCCU professor Beverly McIver tells her story of caring for her mentally 
disabled sister. Adrienne's review.
Modern Family (9pm, ABC) - Gloria learns a secret that Claire has been hiding, and one of Jay's proudest golf moments is ruined by Mitchell.
Happy Endings (9:30pm, ABC) - The end of winter signals "Spring Smackdown," when Jane (Eliza Coupe, right) and Brad (Damon Wayans Jr., right) have their annual domestic dispute.
Royal Pains (10pm, USA) - Hank struggles to accept Jack's illness in the Season 3 finale, and Evan joins Boris' cousin to look into an experimental treatment.
American Weed (10pm, National Geographic Channel) - A new short series that takes an in-depth look at Colorado's medical marijuana industry. Tonight's episode profiles Fort Collins dispensary owners who face the possibility of having their businesses shut down should voters approve Proposition 300.
CSI (10pm, CBS) - The CSIs investigate when a house is stolen from its foundation. Also, Julie displays her skills in blood analysis.
Note: No new "Revenge" tonight.
Brooke Cain isn't always proud of the number of hours she logs in front of the TV, but her loss of brain cells can be your gain. From reality shows to sitcoms to the more serious stuff, Brooke keeps her DVR smoking so that she can help keep you in the know. Brooke also tweets for Happiness is a Warm TV (you can follow