Harry Potter's Alan Rickman and Jimmy Fallon Laugh It Up – on Helium! – on The Tonight Show

Harry Potter fans, rejoice!

Professor Snape, a.k.a. actor Alan Rickman, stopped by The Tonight Show on Wednesday to talk about his movie A Little Chaos – and put the late-night host in the hot seat.

The Harry Potter actor called out Fallon for the time he and Benedict Cumberbatch did an impression of him on the show – a “Rickmanoff,” as it was called. To get Fallon to admit to his ways, Rickman took a page from the Helen Mirren playbook and busted out a truth serum of sorts: helium balloons, which he referred to as “Jimmy Fallon truth-telling machines.”

“I’m very sorry you were offended, I’m very, very sorry,” said Fallon, “and welcome to the show.”

Rickman then inhaled as well: “Apology accepted,” he said.

Rickman and Fallon took it all in good fun, and, in a final plea, Fallon said he and Cumberbatch are big fans of Rickman’s.

To which the actor jovially responded: “Huh.”

The Tonight Show Starring Jimmy Fallon airs weeknights at 11:35 p.m. ET on NBC.