So our party, the Anime Hero Cleric, the Deranged Ranger, the Angry Sorcerer, the Cowardly Rogue, and the Really Freaking Weird Artificer, were camped out with the military. Ever since our battle with the Elvish Slavers, much of the party was coming unhinged due to PTSD, most of all the Ranger. He was beginning to hear voices and had become friends with a squirrel. Now while Speak With Animals is a thing, the squirrel (apparently named Watson) definitely did not have the Intelligence score to describe complex geopolitical situations to the Ranger, so the Artificer and the Cleric knew he was off the deep end.
The Artificer asked the Cleric to do something about it, and the Cleric knew exactly what to do. So the Cleric went to the Rogue and hired him to assassinate the squirrel. He paid 50 gp upfront, and would give the rest after the Rogue produced a corpse.
The Rogue snuck into the Ranger's tent and grabbed the squirrel without waking him up. He took it out to the woods where he was going to murder it, but then got cold feet and couldn't go through with it. He vowed to let the squirrel go. But as he walked away, an owl came out of nowhere and snatched up the poor, defenseless squirrel and ate him.
The next morning, the Ranger woke up and became completely unhinged. He was shouting "KILL KILL KILL" and was threatening to destroy everything. The Sorcerer slowed him down with a Ray of Frost and the Cleric knocked him out. The Cleric then looked to the Artificer and told him he had taken care of it.
They took the Ranger to the infirmary to be treated for his mental condition, and then went off on the mission assigned to them by their Douchebag Paladin Commander. They were about a day's journey away when confronted by the mortal enemy. The enemy told them that they had been betrayed by their commander, and that an army of undead was descending on their camp.
They returned as quickly as possible and helped to route the army, but it was too late. Some undead had murdered the Ranger who was tied up in a straight jacket in the infirmary unable to defend himself.
And that's how a dumb fucking squirrel got our Ranger killed by the poor decision making of his own party.