For the first time ever, the casts of Law & Order, Law & Order: SVU, and Law & Order: Organized Crime will come together for a three-hour event. The mashup will debut on Thursday, Sept. 22. and will feature cast members from all three shows in one intertwined story.

The crossover event is sure to be the start of an explosive season.

“This unprecedented scheduling block is a tribute to all the ‘Law & Order’ fans who’ve been watching this iconic brand for four decades on NBC,” said Lisa Katz, President, Scripted Programming, NBCU Television and Streaming in a statement. “We couldn’t be more excited to open our season with such a historic event.

“Nothing demonstrates the power of the ‘Law & Order’ brand more than an ambitious three-hour event with a story that is truly ripped from the headlines that starts on Organized Crime, then migrates to SVU and finally the trial on Law & Order,” said Dick Wolf said. “Rick and Gwen did an amazing job writing a compelling script and I can’t think of a bigger and better way to launch the new season of ‘Law & Order’ Thursday.”

Here's the description:

As the telecast begins, a mysterious young girl is shot in cold blood and Det. Frank Cosgrove (Jeffrey Donovan) teams up with Det. Jalen Shaw (Mehcad Brooks, first episode) to track down her killer. Capt. Olivia Benson (Mariska Hargitay) and Det. Elliot Stabler (Christopher Meloni) are called in to help when they realize they have more than a typical homicide case on their hands. After uncovering key evidence, Jack McCoy (Sam Waterston) and ADA Nolan Price (Hugh Dancy) seek justice against an international crime ring, but complications threaten the outcome of their case.

Watch the promo below:

The three-hour block was written by Rick Eid  and Gwen Sigan.

The first two episodes are directed by Jean de Segonzac with Alex Hall directing the last one. The franchise is produced by Universal Television, a division of Universal Studio Group, in association with Wolf Entertainment.