The casts of Chicago Fire and its cop-show spinoff Chicago PD have come together in crossover episodes before, but this week’s two-part crossover will take both shows to the very edge after a massive explosion rocks a Chicago hospital.

ET Canada“s Natasha Gargiulo was on the set to speak with Chicago Fire“s Taylor Kinney and Jesse Spencer (Chicago Fire), as well as Chicago PD“s Jason Beghe, Jon Seda and Sophia Bush, and they reveal the upcoming crossover is like nothing viewers have seen before.

“We’ve been doing a lot of crossover,”; says Sophia Bush, who plays Det. Erin Lindsay, “but to do this big event episode where every single person is on set together at once is so exciting for all of us.”;

As Taylor Kinney (Chicago Fire“s Kelly Severide) explains, the Fire and PD crews are brought together in the aftermath of what appears to be a terrorist attack. “There’s a blast and we don’t know if it’s inside the hospital or if it’s a terrorist or from anything,”; Taylor says. “We just know that it’s bad.”;

Adds Jesse Spencer, who plays firefighter Matthew Casey, “When the explosion happens, there’s just chaos.”;

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Meanwhile, the stars say these two episodes are nothing less than cinematic in scope, rivaling anything you’d see at your local multiplex. “It looks like a $100-million feature,”; says Jason Beghe, who plays Chicago PD“s Sgt. Hank Voight.

“It’s epic,”; adds Chicago PD“s Jon Seda (Det. Antonio Dawson). “It’s big — it’s something that you rarely see on TV… it just raises the bar on everything.”;

The two-part crossover begins on tonight’s episode of Chicago Fire, airing Tuesday, Apr. 29 at 10 p.m. ET/PT p.m. Global. The stunning conclusion can be seen the following evening, on the Wednesday, Apr. 30 episode of Chicago PD, airing at 10 p.m. ET/PT on Global.

You can catch Natasha’s interview on tonight’s edition of ET Canada, airing at 7:30 p.m. ET/PT on Global.

In the meantime, find out how much the Chicago PD stars know about the Windy City with this Chi-Town quiz! Watch below.