TOP CHEF DUELS: Dale Talde and Tiffani Faison face off in the latest installment. (Nicole Wilder/Bravo)

RETURNING SHOW: “Hell’s Kitchen” (Fox at 8 p.m.) opens Season 13 with Gordon Ramsay splitting the 18 aspiring chefs into two teams (men vs. women) and challenging them to create their signature dishes. In the second hour, Ramsay demands that they make his signature geoduck sashimi, which sounds like a children’s video game gone wrong but is apparently difficult to master.

“NOVA” (WETA at 9) presents the topical documentary “Vaccines — Calling the Shots,” an examination of how vaccines work and why they are so critical to a healthy society. The film also looks at the anti-vaccine movement, which about 10 percent of the American public supports.

The 2011 film “Children of 9/11: Revealed” (WHUT at 9) allows the children who lost a parent in the attacks speak publicly for the first time as adults. The one-hour documentary features four families who, between them, lost three fathers and a mother and all responded to the tragedy in remarkably different ways.

The penultimate episode of “Extant” (CBS at 10) attempts to tie up as many loose ends as possible with Molly finally meeting her offspring, but that, of course, unleashes a whole new mystery.

FINALE WATCH: Tragedy strikes when Leo’s son and daughter-in-law visit and Cat must close a case on the Season 1 finale of “Taxi Brooklyn” (NBC at 10).

“Operation Maneater” (MPT and WETA at 10) zeros in on the crocodile with a visit to Namibia’s Chobe River, where croc attacks are fairly commonplace and scientists are attempting to reduce those attacks by training the reptiles to associate the sound of a bell with an electric shock.

Dale Talde challenges Tiffani Faison to make dumplings and in turn, she asks Talde to serve up an American canape and cocktail on “Top Chef Duels” (Bravo at 10). Rob Zombie judges for reasons unknown.

“Restaurant: Impossible” (Food at 10) hits close to home with Robert Irvine & Co. heading to Falls Church, Va. to get the Vietnamese restaurant Spicy Bar and Grill out of $300,000 in debt.

“The Colbert Report” (Comedy Central at 11:30) welcomes former secretary of state Henry Kissinger.

Actors Hugh Jackman and Nick Offerman appear on “The Tonight Show Starring Jimmy Fallon” (NBC at 11:35), with music from Luke Bryan.

TV personality Phil McGraw and “Idol”-turned-actress Katharine McPhee are on the “Late Show With David Letterman” (CBS at 11:35), with musical guests Death From Above 1979.

Queen Latifah swings by “Jimmy Kimmel Live” (ABC at 11:35), with NASCAR driver Dale Earnhardt Jr. and music from Panama Wedding.

Rachel Lubitz