Think you’ve got the right answer? Keep reading to see if you nailed it.

What strange medical condition do Weird Al Yankovic’s 1989 movie UHF and the 1999-2004 UPN supernatural drama Angel have in common?

Bell’s palsy is a temporary form of facial paralysis, generally affecting a small area of the face, or as much as half. A nerve in the brain stops firing (scientists aren’t sure why, but many believe a virus is to blame), so the brain cannot control facial muscles for as long as a few weeks. The condition almost always clears up on its own over time.

An actor’s instrument is their face, and when an actor gets Bell’s palsy, it can certainly cause problems if they’re in the middle of a production. This happened on both the set of the movie UHF and the TV series Angel.

• After starring in a dozen comic music videos and hosting specials on MTV, Yankovic made a movie called UHF in 1989. The plot: a man inherits a small TV station and airs bizarre programs, including Stanley Spadowski’s Clubhouse, a kid’s show hosted by the station’s manchild janitor. Michael Richards played Stanley, just before he’d become a star as Kramer on Seinfeld. But he almost had to turn down the role. Just before filming, he contracted Bell’s palsy, and half of his face was frozen. He called Yankovic to resign, who wouldn’t hear it—he thought a half-frozen face would be a fine addition to his already odd character. Richards ultimately saw an acupuncturist, who he says made the palsy disappear in two days, and filming was unaffected.

• In 2004, just before filming was to start on the fifth season of Angel, a supernatural drama about a vampire and his cohorts taking over a lawfirm run by demons, co-star Alexis Denisof was diagnosed with Bell’s palsy. The left side of his face was paralyzed, requiring Angel producers to devise new ways of filming him, to avoid showing his unmoving face. It also made writers have to reconsider Wesley Wyndam-Price, his character. Often a manic, high-strung source of comic relief, writers were forced to make Wesley more pensive, brooding, and quiet. (The palsy went away, but the character traits remained.)

Want more impossible questions? Check out Uncle John’s Impossible Questions.