SPOILER ALERT: The following story reveals major plot points from tonight’s FBI and FBI: International crossover event on CBS.

Weddings are tough enough without having to worry about the entire thing getting bombed, but that’s exactly what happened to an unlucky couple and their loved ones in CBS’ FBI, FBI: International and FBI: Most Wanted global crossover tonight.

One of the only survivors is the bride’s father, a Belarusian general hell-bent on getting revenge against the Americans he blames for the blast. Three months after the wedding, an Italian was murdered and his American colleague went missing in Rome, a case that brings FBI‘s Jubal Valentine (Jeremy Sisto) and FBI: International‘s Scott Forrester (Luke Kleintank) together in Italy.

Jubal and Scott working together made for a great episode; in an alternate universe, they’d have made great partners. Luke is patient and strategic; he always knows when it’s best to play the long game. Jubal knows how to push people’s buttons to get what he needs, and he’s got that New York swagger that lets others know he isn’t there to mess around. Together, and later with the help of Remy Scott (Dylan McDermott), they’re hot on the case of the bad guys but time is running out.

Sisto and Kleintank spoke to Deadline recently about various key moments from the first two episodes and revealed the secret to their characters’ compatibility lies plainly in how great the actors get along in real life.

DEADLINE: Jeremy and Luke, what was it like going to Rome and meeting for the first time?

JEREMY SISTO: Yeah, we got crazy in Rome! No, not really. I brought my 10 and 13-year-old and my beautiful wife, and Luke has a beautiful young baby girl and a beautiful wife, as well. Everyone was beautiful, you should know that. We shared some dinners and we shot all around Rome. I wasn’t there for those shots in front of the Colosseum, but we shot every day on these quintessentially Roman cobbled streets with beautiful shadowed street lights. It was really great.

LUKE KLEINTANK: We shared a lot of stories and it was nice to meet Jeremy’s family. Man, you’ve got some cool kids. We did a lot of night shoots together, and, at one point, we were delirious. We shared a green room and we had these two little beds next to each other. Jeremy showed me his music, he’s a great musician. If you haven’t heard his music, you should check it out.

SISTO: We probably had deeper conversations than I’ve had with most of the cast which tends to happen when you work on location. With Luke and I sharing what was like a dorm room, we connected on a lot of different levels. It was also cool working with the cast and crew; it was a trip to have me jump into their world. Their show is a version of what we do but in a different environment. The crew were from different nationalities: there were lots of Hungarian crew with them, and also some from Italy. Working with that other sensibility and culture was energizing for me. It was really quick for us to get into a good rhythm together.

DEADLINE: What can you guys share regarding the difficulty of putting together a major crossover event like this, which has a movie-quality feel to it?

KLEINTANK: I got to give it up to our crew, our director Michael Katleman and to our DP. Everybody did such a great job. That’s the caliber we try to hit with each episode. You’re gonna see that in the next episode and the next episode. You know, it’s not fair because we have Europe as a backdrop so it’s not just New York. So, in the lens that looks amazing.

SISTO: Hey, New York is an amazing backdrop. Give me a break! We have some rich and sorted history here, too. [Laughs] Back to that wedding we open with, it’s a powerful and emotional, and poignant way to start our story. They put a lot of energy into coming up with this story that will represent these three shows and tie them together in a believable way. We wanted you to feel like you were watching a big movie. I was impressed with how much time and thought they put into this.