Treehouse Masters (10 p.m., Animal Planet) – Pete and the gang build a clubhouse for Long Island’s Sunrise Day Camp, a camp for children battling cancer. The clubhouse includes a crow’s nest outpost and a peek-a-boo roof for full interaction with nature.
Also on tonight . . .
We Day (8 p.m., ABC) – A celebration of young people who are dedicated to changing the world. Expect stars like Jennifer Hudson, Common, Selena Gomez, The Band Perry, Demi Lovato, Nick Jonas, Colbie Caillat, Paul Rudd and Macklemore.
Cold Justice (8 p.m., TNT) – The team investigates the death of a mother found in her car after an explosion in Johnson County, Iowa, in 1995.
Killjoys (9 p.m., Syfy) – The season ends with tensions boiling over when the Company arrests a friend.
Dog with a Blog (9 p.m., Disney) – Stan wonders what it would be like to be a cat instead of a dog after accidentally ruining Ellen’s new couch.
Cold Justice: Sex Crimes (9 p.m., TNT) – Casey and Alicia continue working cold cases in Flint, Mich.