Monday's Highlights: 'Castle' on ABC
Drew Carey's Improv-A-Ganza: In this new series, Carey and friends put on an improvised sketch comedy show (5 and 8 p.m. Game Show Network).
Civil Warriors: In this new series, descendants of soldiers and others who played a role in the Civil War use their ancestors' writings to get a taste of what they experienced (5, 6 and 7 and 8, 9 and 10 p.m National Geographic).
Seriously Funny Kids: Heidi learns the benefits of getting older in the season finale (6 p.m. Lifetime).
The Secret Life of the American Teenager: Last week, Ben (Ken Baumann) was thinking about asking Adrian (Francia Raisa) to marry him, in this new episode, he pops the question (8 and 10 p.m. ABC Family).
Law & Order: LA: Big changes are afoot as the crime drama returns with a two-hour episode. Skeet Ulrich and Corey Stoll also star (9 p.m. NBC).
Being Human: The season finale flashes back frequently to important moments in the friendship of Aidan and Josh (Sam Witwer, Sam Huntington); Nora (Kristen Hager) learns the truth about Josh; Sally (Meaghan Rath) regains the power of physical touch, while Aidan prepares for his final showdown with Bishop (Mark Pellegrino) ” (9 p.m. Syfy).
Cake Boss: Mauro is in charge while Buddy is away for surgery in the season finale (9 p.m. TLC).
Paranormal State: Ryan Buell and the Penn State University-based Paranormal Research Society return for another season of investigating unusual phenomena (10 and 10:30 p.m. A&E).
Intervention In-Depth: Hillbilly Heroin: This new special visits Ohio's Scioto County, which has seen a 360 percent increase in drug overdose deaths, and 90 percent of those involve prescription painkillers. (8 p.m. A&E).
Baseball: The Tampa Bay Rays visit the Boston Red Sox (4 p.m. ESPN); the Dodgers visit the San Francisco Giants (7 p.m. KCAL); the Cleveland Indians visit the Angels (7 p.m. FSN).
Photo: Matt Kennedy / ABC