A "Star Trek" alum will go head-to-head with Patrick Jane on "The Mentalist."

On the upcoming episode, Jane (Simon Baker) and the FBI will try to prove a death row inmate's innocence before his impending execution.

"Star Trek's" John De Lancie will play the widow of the woman who was murdered, so "he and Jane square off over that," said executive producer Tom Szentgyorgyi.

"John gives a spectacular performance, and was a great sparring partner for [Simon] Baker," he added.

Watch an exclusive clip from the next episode here.

And as for Jane's reaction to his ex's new love, the EP said he will begin to feel "like a third wheel."

"I think Jane was feeling curiously like a third wheel - something he doesn't feel very often - and wondering why he felt that way," Szentgyorgyi said. "Pike is with us through the end of the season, and he will become a increasingly important figure in Lisbon's life, so Jane is wondering what he's feeling, because he's been the most important man in Lisbon's life - and suddenly he might not be."

On the latest episode before the show's brief hiatus, Jane and Lisbon teamed up to catch murderous art thieves.

In "Violets," the FBI is investigating the death of John Hennigan, the owner of an art gallery. He was killed by a group of art thieves, who then stole a bunch of his paintings. Jane tells Abbott (Rockmond Dunbar) about the case, thinking they should work together to track down the thieves.

The FBI art theft squad is also working on the case, which includes special agent Marcus Pike (Pedro Pascal). Pike says they have been looking for the thieves for awhile, but they have only identified one of them.

Jane then comes up with a plan to go undercover to lure the thieves to seal expensive art, then catch them in the act. Jane and Lisbon (Robin Tunney) go undercover as a cultured married couple who own a large home full of expensive art. Abbott, Fisher (Emily Swallow), Cho (Tim Kang) and Wylie (Joe Adler) are also involved in the sting.

Meanwhile, Pike is showing some noticeable interest in Lisbon.

Jane's plan works, and the FBI is able to capture the rest of the art thieves, including the boss, who killed Hennigan.

Afterwards, Pike asks Libson out for dinner, and Lisbon agrees. Jane finds out that the two are going out on a date, and he is clearly not happy about it.

On the next episode, "Silver Wings of Time," "With only two days before a man is executed, the FBI and Jane attempt to solve a cold case and prove the man is innocent."

Watch the promo below for "Silver Wings of Time," which airs Sunday, April 13 at 10 p.m. EDT on CBS.