‘NASHVILLE’: Scarlett's (L) breakdown is driving everyone to point fingers at who might be responsible for her condition, while Rayna (R) rushes in to help. (Mark Levine/ABC)

A castaway with an intense strategy could throw off the food auction competition on “Survivor” (CBS at 8 p.m.), while another castaway attempts to show off his immunity idol to save him from elimination.

The Top 5 perform on “American Idol” (Fox at 8), and Jason Mraz plays guest judge.

Miles is injured following an altercation with the Texas Rangers on “Revolution” (NBC at 8), and Neville continues his search for Jason.

“Who Wore It Better?” (E! at 8) gives an inside look into how some celebrities end up wearing similar outfits on the red carpet, even with access to a stylist and gratis designer duds.

Phil invents an elaborate lie and finds himself unable to keep it up against a pressured and suspicious Claire on “Modern Family” (ABC at 9).

The “Criminal Minds” (CBS at 9) team is onto a strange and threatening case when several victims of arsenic poisoning are found in Long Beach, which then leads them to a killer obsessed with Greek mythology.

Clarke and Raven make vital contact with the Ark, so then Abby assists Clarke with a dangerous procedure so they can save one of their own on “The 100” (CW at 9).

After Scarlett suffers a career-halting breakdown, Rayna comes to her aid on “Nashville” (ABC at 10), while Scarlett remains preoccupied with Avery, who’s too concerned about Scarlett to care about any drama she’s looking to stir up.

A new mission with international stakes is introduced to the Jennings family on “The Americans” (FX at 10).

“Nazi Mega Weapons” (MPT and WETA at 10) focuses on the enormity of German tanks, some of which weighed 180-plus tons, and a plan by Hitler to make a land battleship weighing 1000 tons.

The FBI’s Cyber Crime Division visits “CSI: Crime Scene Investigation” (CBS at 10) when a well-known casino mogul’s wife is found dead.

Actors David Spade and Sophia Bush are on “The Tonight Show Starring Jimmy Fallon” (NBC at 11:35), with a musical performance from The Both.

Actor Kiefer Sutherland comes to the “Late Show With David Letterman” (CBS at 11:35), along with comedy writer Adam Resnick and music from Benjamin Booker.

Actors Leslie Mann and Tony Hale stop by “Jimmy Kimmel Live” (ABC at 11:35), with musical guest Franz Ferdinand.

Rachel Lubitz