Chasing Life (9 p.m., ABC Family) – In the second season opener, a fellow cancer patient gives April the impetus to live in the moment, and Natalie finds a secret manuscript of her father's that could impact the entire family.
Also on tonight . . .
Penn & Teller: Fool Us (8 p.m., CW) – In the second season premiere, aspiring magicians who perform for Penn and Teller include Jon Armstrong, Xavier, and Greg Dow.
Major Crimes (9 p.m., TNT) – The unit investigates a complicated shooting, and Det. Sykes must protect the identity of a witness.
Tough Love (10 p.m., UNC-TV) – In this POV documentary, two parents fight to win back custody of their children.
The Whispers (10 p.m., ABC) – Claire talks to a group of kids who have been contacted by Drill, and there's a breakthrough.
UnReal (10 p.m., Lifetime) – Adam meets Mary's family when the show arranges their one-on-one date.
Teen Wolf (10 p.m., MTV) – Scott tracks a dangerous shapeshifter that has been threatening Stilinski.