I have lost faith in the human race. From the BBC:

A man on a Greyhound bus travelling across the Canadian Prairies has killed and decapitated a fellow passenger.

An eyewitness said the victim was stabbed 50 or 60 times by the man sitting next to him, who then severed his head with a large knife.

[…]

“When we came back on the bus… he was cutting the guy’s head off and pretty much gutting him up,” Mr Caton said.

The attacker ran at them, Mr Caton said, and they ran out of the bus, holding the door shut to prevent him getting out.

“He calmly walks up to the front [of the bus] with the head in his hand and the knife and just calmly stares at us and drops the head right in front of us,” Mr Caton said.

“There was no rage in him … It was just like he was a robot or something,” he added.”