Lily Tomlin narrates and is executive producer of the documentary “An Apology to Elephants” (HBO at 7 p.m.), which looks at some of the unsavory things humans have done to the elephant population over the years — namely, capturing them and training them in captivity, and destroying their habitat. “The first thing we need to know is that the elephants need our help,” Tomlin says in the film, which looks at how elephants are at risk for extinction, partly because of the ivory trade.

In this season’s penultimate episode of “Bones” (Fox at 8), the team has to find out who killed a journalist and left her body at a biohazard facility, trying to cause a viral outbreak.

Although no one’s really into the idea, Jen makes sure the guys throw a bachelor party for Adam on “Rules of Engagement” (CBS at 8:30); while that's happening, Jen paints a mural for Audrey and Jeff’s nursery, but the picture gets a little graphic.

SERIES PREMIERE: The drama “Rectify” (Sundance at 9), about a man who is released after 20 years on death row and returns home to his family, is reviewed by Hank Stuever on Page C3.

SERIES PREMIERE: Some people just watch TV to relax — but if you want to watch an hour of trickery that explains how easily the brain can be fooled, tune into “Brain Games” (National Geographic at 9, 9:30) for some puzzles.

A number of followers put on disguises to infiltrate the town’s evacuation center on “The Following” (Fox at 9), which leads to an FBI official being kidnapped while Ryan and the team are busy getting ready to storm the follower mansion.

FINALE WATCH: On the Season 3 finale of “Lost Girl” (Syfy at 10), Bo — the succubus who feeds off sexual energy — tries to rescue two people she loves, although that means putting others in danger. Meanwhile, Dyson discovers a surprising clue about Bo’s past — and get ready for cliffhangers, because the show has already been renewed.

“The Late Show With David Letterman” (CBS at 11:35) hosts actor Matthew McConaughey and swimmer Ryan Lochte, with a performance by Steve Earle.

Actress Diane Keaton and actor Trevor Moore are on “The Tonight Show With Jay Leno” (NBC at 11:35), along with singer Jake Bugg.

“Jimmy Kimmel Live” (ABC at 11:35) hosts actor Dennis Quaid, actress Abigail Spencer and musical guest Portugal. The Man.

— Emily Yahr