Worlds Collide: 15 Times Your Favorite Characters Appeared On A Different Show

In a two-part crossover event entitled "Pandora's Box," Pride and Lasalle made cameos on NCIS to shed light on a homeland security operation gone awry with Abby.

Watch NCIS on Tuesdays at 8/7c on CBS and CBS All Access.

In part two of "Pandora's Box," NCIS Special Agents McGee and Torres visited the New Orleans team to tie up loose ends on the homeland security case from the previous episode, which found them in search of a missing terror playbook.

Watch NCIS: New Orleans on Tuesdays at 10/9c on CBS and CBS All Access.

Walter O'Brien and the rest of Team Scorpion enlisted NCIS: Los Angeles' Hetty Lange when a case involving a priceless painting took them to a Halloween party. Her expertise helped them go undercover and infiltrate the event.

Watch Scorpion on Mondays at 10/9c CBS and CBS All Access.

Special Agent Anthony DiNozzo (Michael Weatherly) is best known for his work in and around Washington, DC, for NCIS, but he's also visited the City of Angeles to work with the NCIS: Los Angeles team. He came to town expecting to help with a routine prisoner transport, but when things took a turn he enlisted help from the Office of Special Projects.

Check out some more of your favorite characters who have appeared on multiple shows...

Watch NCIS: Los Angeles on Sundays at 8/7c on CBS and CBS All Access.

When a bus transporting Naval prisoners to Charlotte had an accident, three of the prisoners escaped. When Pride learned that one of them is not actually a Navy man, he contacted Gibbs and Vance. They tell him that the suspect is involved in espionage—and they were just about to question him.

Watch NCIS: New Orleans on Tuesdays at 10/9c CBS and CBS All Access.

NCIS Special Agent Tony DiNozzo came in from DC to assist the New Orleans team when a Navy Lieutenant died of the bubonic plague in "Carrier" (Season 1, Episode 2).

Watch NCIS: New Orleans on Tuesdays at 10/9c on CBS and CBS All Access.

When a family of four was abducted while on vacation in Barbados, the BAU was called in to assist Jack Garrett and his International Unit on their investigation in Criminal Minds: Beyond Borders. Garrett and his unit, the FBI's top division for handling cases involving Americans abroad, worked jointly with Hotch and his team when they discovered that this case matched one the BAU investigated the year before in Florida.

Watch Criminal Minds on Wednesdays at 9/8c on CBS and CBS All Access.

Matthew Simmons also joined Chief Jack Garrett when a family of four was abducted while on vacation in Barbados in "Beyond Borders."

Watch Criminal Minds on Wednesdays at 9/8c on CBS and CBS All Access.

On NCIS: Los Angeles' "Touch of Death," the team gets an assist from Hawaii Five-0 when a lead suspect arrives on the mainland with a deadly virus in tow.

Watch NCIS: Los Angeles on Sundays at 8/7c on CBS and CBS All Access.

In a two-part crossover event entitled "Sister City," the NCIS and NCIS: New Orleans teams partner up to solve a case involving Abby's brother Luca.

Watch NCIS: New Orleans on Tuesdays at 10/9c on CBS and CBS All Access.

CSI's D.B. Russell lent a hand to his CSI: NY friend Mac Taylor when they needed to find out why Taylor's girlfriend was missing in "In Vino Veritas."

Watch episodes of CSI on CBS All Access.

After a 10 year stint on The Young and the Restless, Judith Chapman (aka Gloria Fisher Bardwell) made the trek from Genoa City to Los Angeles to support pal Eric Forrester on The Bold and the Beautiful.

Watch The Bold and the Beautiful weekdays on CBS and CBS All Access.

Caroline Forrester (Linsey Godfrey) and Rick Forrester (Jacob Young) crossed over from The Bold and the Beautiful to The Young and the Restless for Chelsea's fashion show in 2014. The duo is pictured here with Chelsea Lawson (Melissa Claire Egan).

Watch The Young and the Restless weekdays on CBS and CBS All Access.

Eric Forrester (John McCook) crossed over from The Bold and the Beautiful to The Young and the Restless for Victor and Nikki's 2013 wedding. Eric is pictured here with Victor Newman (Eric Braeden) and Neil Winters (Kristoff St. John).

Watch The Young and the Restless on CBS.