The Tonight Show Starring Jimmy Fallon

The "Boomerang" singer also told Jimmy Fallon why his ride is her "favorite place in all of Universal Studios Orlando."

The former One Direction member brought a chill vibe to The Tonight Show, singing a track from his latest solo album, Room Under the Stairs.

Chaos ensued when The Tonight Show Host learned a bit of Kit Kat Club choreography.

Think the trio can't Michael McDonald-ify "Row, Row, Row Your Boat"? That's "What A Fool Believes"!

"If anyone knows how to get in touch with Ariana Grande, let me know!"

"I think it's if not the best, one of our best episodes ever," revealed the Chicago P.D. star.

The One Chicago star joined Jason Beghe and S. Epatha Merkerson for a pre-finale chat on The Tonight Show Starring Jimmy Fallon. 

"A little bit about me: I love opening a fresh jar of organic peanut butter just so I can guzzle the oil on top."

Their story involves Fred Armisen, a Paul Weller concert, and a friendship that dates back to Fallon's Saturday Night Live days.

The British heartthrob had quoted Samuel L. Jackson from the original Jurassic Park in a foreshadowing Instagram post.