WATCH: The Siren cast says musical theatre is more fun in prison

The walls are closing in on Siren, quite literally! In the latest episode of the Freeform original series, Ben, Calvin, Xander, and Chris were locked up under suspicion of murder. Not even Ben's fake confession could get the other guys out of trouble, and it led to some tense moments.

However, things were considerably more funs behind the scenes. In SYFY WIRE's latest Siren exclusive video, the cast revealed that one of their own used the set as a chance to fulfill his musical dream.

"I think it might have been Ian's idea," said Alex Row. "Halfway through when we're taking a little break, he's holding on to the bars doing the full Chicago dance routine, which is very impressive."

"I'm totally the musical theatre nerd," added Ian Verdun, as he confirmed Row's account. "That was just like, 'okay! This is the perfect time to get all of my Chicago fantasies out.'"

Verdun also noted that prison set wasn’t quite as impressive as it may have looked on TV.

"It was also quite flimsy too," recalled Verdun. "There were a couple of times when you're trying to do pull ups on the top bars... and you're starting a bow, it's like 'okay, let's not break the set!' Because we almost broke the set last year... we didn't want a repeat."

Ultimately, it took a sacrifice from Ryn to free her friends from prison. But the ramifications from that are only beginning to play out.

For more details, you can check out the entire clip! Siren airs Thursdays at 8PM on Freeform.