The last time Tim heard that, it was loosely disguised code for 'let's go kill a whole bunch of people.' He instinctively opened his mouth to ask whether or not that was really a good idea, and stopped when Jack actually did just... stride away. No guns. No threats. He was practically having fun.

If he was having fun, then Tim needed to have fun as well.

He took a breath, pasted on the smile - that particular smile, the one Jack wore about ninety percent of the time, the cross between amusement and scorn - and followed after him.