Mindreader Anthony Laye plays a game called "nailgun roulette," where he tries to tell by a person's voice which one of four nailguns is loaded. Hopefully, he's right, because the other three are going to be fired at him.
But Laye isn't the one in real danger here. Studio 10 presenter Sarah Harris, who had the nervewracking job of shuffling the four guns around, wasn't paying attention when Laye explained which end of the nailgun was which, leading to an extremely tense situation.
This entire segment could have gone worse for both of them, in so many Darwin Award-winning ways.