Under the Dome
The mysterious drama sprung from the mind of Stephen King returns for its second season with this new episode. Barbie's (Mike Vogel) life is in Big Jim's (Dean Norris) hands, while Julia (Rachelle Lefevre) seeks the help of a stranger to save a life. CBS/Global, 9 p.m.
Gail & Me: 40 Years on Coronation Street
This new special looks back on actress Helen Worth's four-decade run on the venerable Brit-import soap. Past and present castmates, including Jack P. Shepherd, Sue Nicholls, Paula Lane and Brian Capron, offer tributes. CBC, 7 p.m.
24: Live Another Day
The threat has proven to be more complex than initially thought, and Jack and Chloe must adapt in this new episode. Kate is pushed even further, and Audrey faces tough choices. Fox/Global, 8 p.m.
George Stroumboulopoulos: Gary Shteyngart
David Letterman: Louis C.K., Amy Sedaris
Jimmy Fallon: Ricky Gervais, Miranda Lambert
Jimmy Kimmel: Melissa McCarthy, Marc Maron
Craig Ferguson: Ricky Gervais, Lauren Cohan
Seth Meyers: Daniel Radcliffe, Jessica St. Clair
Conan O'Brien: John C. Reilly, Pete Holmes