Mafia 46. Lord of the Rings.

Mold, we don't know which of you two is Barlog, but there's a 95% chance that one of you is. We need to execute someone; I personally don't know who, but you currently have more votes, which means there's a higher chance that we'll hang someone today. See, I haven't cast my vote yet; I'll do it in the evening, in case everyone decides to execute Wishmaster.

I can't wrap my head around it: even if Ple-Sen is the maniac who killed Lurz and Saruman, what prevents Gandalf from killing him the next night?

Nothing prevents him, but Gandalf will die himself if he doesn't use his upgrade. And he probably doesn't want that. And if he uses this one-time ability and misses Barlog, he'll never kill him again without harming himself.

By the way, Ancient! You can heal Gandalf, right? This means that not all is lost, but there's one problem: we don't know who Gandalf is. And besides, he's not really needed, because Saruman is dead (presumably), and we'll hang Barlog soon.

However, we can take a risk. If we hang, for example, Mold now, and he escapes execution (turns out to be Barlog), then Gandalf will kill him at night to save time on execution during the day, and also to prevent him from killing someone at night. If we hang Mold and he doesn't escape (he's not Barlog), then Gandalf will risk using his ultimate ability and go to Wishmaster, hoping that he is Barlog.