‘FBI,’ ‘Most Wanted’ & ‘International’ Team Up for 3-Part Crossover Premiere (PHOTOS)

Julian McMahon, Zeek Zaki, Missy Peregrym in 'FBI: Most Wanted'
Mark Schfer / CBS

Just how big is a case that it requires agents from FBI, FBI: Most Wanted, and FBI: International to solve it? Well, it involves murder, a criminal enterprise, and a teenage girl in trouble overseas.

It all begins on Tuesday, September 21 on FBI with the murder of a young woman on her way home from a lavish yacht party attended by very influential people in the Season 4 premiere, “All That Glitters.” Maggie (Missy Peregrym) brings in Crosby (Most Wanted‘s Kellan Lutz) when it turns out he worked with a murder suspect on several Army operations. Most Wanted‘s Julian McMahon also guests as Jess LaCroix.

'FBI: International': Meet the Members of the Fly TeamSee Also

'FBI: International': Meet the Members of the Fly Team

Their secret weapon is Tank, team leader Forrester's Schutzhund (German for 'protection dog').

That leads into the Most Wanted Season 3 premiere, “Exposed,” and by then, there’s been another murder. The local FBI case leads to a manhunt for the dangerous leader of a far-reaching criminal enterprise. FBI‘s Peregrym, Zeeko Zaki (Omar Adom “OA” Zidan), and Alana De La Garza (Special Agent in Charge Isobel Castille) guest.

It concludes with the International series premiere, introducing Scott Forrester (Luke Kleintank) and his Budapest-based FBI fly team — Jamie Kellett (Heida Reed), Andre Raines (Carter Redwood), Cameron Vo (Vinessa Vidotto), and Europol’s Katrin Jaeger (Christiane Paul), along with their “secret weapon,” Tank the Schutzhund dog. Isobel sends them to Croatia to chase down the fugitive who escaped to Zagreb with a 14-year-old girl. It won’t be easy, though: the local authorities are going to be less-than-cooperative. OA continues with the mission overseas to bring the fugitive to justice. FBI‘s Peregrym and Jeremy Sisto (Assistant Special Agent in Charge Jubal Valentine) and Most Wanted‘s McMahon and Lutz guest star.

Scroll down for a look at all three episodes.

FBI, Season 4 Premiere, Tuesday, September 21, 8/7c, CBS

FBI: Most Wanted, Season 3 Premiere, Tuesday, September 21, 9/8c, CBS

FBI: International, Series Premiere, Tuesday, September 21, 10/9c, CBS

Missy Peregrym as Maggie and Zeeko Zaki as OA in FBI
Michael Parmelee/CBS

FBI Season 4 Premiere

Maggie (Missy Peregrym) and OA (Zeeko Zaki)

Jeremy Sisto as Jubal in FBI
Michael Parmelee/CBS

Jubal (Jeremy Sisto)

John Boyd as Scola, Katherine Renee Turner as Tiffany in FBI
Michael Parmelee/CBS

Scola (John Boyd) and Tiffany (Katherine Renee Turner)

Zeeko Zaki as OA in FBI
Michael Parmelee/CBS

It’s OA with the save!

Kellan Lutz as Crosby, Missy Peregrym as Maggie, Zeeko Zaki as OA in FBI
Michael Parmelee/CBS

Most Wanted‘s Crosby (Kellan Lutz) pops in to work with Maggie and OA.

Alana De La Garza as Isobel, Zeeko Zaki as OA, Julian McMahon as Jess in FBI Most Wanted
Mark Schäfer / CBS

FBI: Most Wanted Season 3 Premiere

FBI‘s Isobel (Alana De La Garza) crosses over to Most Wanted.

Alexa Davalos as Gaines, Miguel Gomez as Ortiz, Zeeko Zaki as OA in FBI Most Wanted
Mark Schäfer / CBS

Kicking down doors!

Roxy Sternberg as Barnes, Julian McMahon as Jess, Miguel Gomez as Ortiz in FBI Most Wanted
Mark Schäfer / CBS

What are they looking for?

Zeeko Zaki as OA, Alexa Davalos as Gaines, Julian McMahon as Jess in FBI Most Wanted
Mark Schäfer / CBS

OA, Gaines (Alexa Davalos), Ortiz (Miguel Gomez), Barnes (Roxy Sternberg), and Jess (Julian McMahon)

Vinessa Vidotto, Carter Redwood, Heida Reed, Luke Kleintank in FBI International
Katalin Vermes/CBS

FBI: International Series Premiere

Meet the International team.

Heida Reed as Kellett, Luke Kleintank as Forrester, Vinessa Vidotto as Vo, Carter Redwood as Raines in FBI International
Katalin Vermes/CBS

Special Agent Jamie Kellett (Heida Reed), Special Agent Scott Forrester (Luke Kleintank), Special Agent Cameron Vo (Vinessa Vidotto), and Special Agent Andre Raines (Carter Redwood)

Christiane Paul, Luke Kleintank in FBI International
Nelly Kiss/CBS

A look at how the fly unit works

Christiane Paul, Heida Reed, Luke Kleintank in FBI International
Katalin Vermes/CBS

Have they run into some trouble with the locals?

Heida Reed as Kellett, Luke Kleintank as Forrester in FBI International
Katalin Vermes/CBS

It looks like they’ll need help from those who do carry guns in this instance.

The fly unit and Tank in FBI International
Nelly Kiss/CBS

The fly unit and their secret weapon, Tank