Eddie Kaye Thomas Guest Stars on ‘Law & Order: SVU’ (PHOTOS)

The Law & Order: SVU squad has a tough case on its hands for what has ended up being the penultimate episode of Season 21. (But hey, at least we know that it will be back for three more seasons!)

In “Solving for the Unknowns,” Olivia (Mariska Hargitay) and the squad struggle to find a serial predator who uses a date rape drug that doesn’t leave any evidence behind. Therefore, there’s nothing they can test for, which makes it quite difficult for everyone involved.

In fact, in the promo (below), Carisi (Peter Scanavino) warns, “figure out what is going on, or I’m going to have to drop this case.”

Guest stars for the episode include Natalie Smith, Daniel London, Madison Ferris, and Eddie Kaye Thomas (who appeared in two Law & Order episodes). Thomas is in both the preview and the photos. “I did not give them any drugs,” his character, Luke Remsen, insists, but they must have something on him since he’s been brought in for interrogation.

But it’s not all doom and gloom. Also in this episode, Rollins (Kelli Giddish) receives some good news.

Law & Order: SVU, Thursdays, 10/9c, NBC