You, Me and the Apocalypse As a comet heads toward Earth, an unlikely group of survivors makes its way to safety in this new series starring Rob Lowe, Jenna Fischer and Megan Mullally. 8 p.m. NBC
DC's Legends of Tomorrow In Part 2 of the two-part series premiere, the united heroes find themselves surrounded by criminals. 8 p.m. KTLA
American Idol Hollywood week continues in this new episode. 8 p.m. Fox
The 100 Kane and Bellamy (Henry Ian Cusick, Bob Morley) risk their lives to rescue Clarke (Eliza Taylor), while Murphy (Richard Harmon) schemes to betray his ex-commander...