“Dexter” — Prime time’s favorite serial killer (Michael C. Hall) enters his eighth and final season and something’s got to give. Will he finally get caught? Will he confess? Will he die? Oh, so many questions. The opener picks up six months after Dexter’s sister, Deb (Jennifer Carpenter), killed Capt. Maria LaGuerta  to protect his murderous secret. Now, she’s an emotional wreck, and he’s feeling responsible. 9 p.m., Showtime.

Chris Tucker is the host for the “BET Awards 2013,” which celebrates achievements in music, acting and sports. Performers include Chris Brown, Mariah Carey, Stevie Wonder, Nicki Minaj and Justin Timberlake. 6 p.m., BET.

“Masterpiece Mystery!” continues with the further exploits of “Inspector Lewis.” The latest episode has Lewis and Hathaway (Kevin Whately and Laurence Fox) investigating the murder of a chemistry professor who had been just released from prison. 8 p.m., PBS.

In “Ray Donovan,” Liev Schreiber delivers an Emmy-worthy performance as a cool, swaggering Hollywood “fixer” who cleans up the messy scandals of his celebrity clients. The stellar cast includes Jon Voight and Elliott Gould. 10 p.m. Showtime.