One thing they had to worry about was a butterfly effect. Make a few tiny changes here and it could spread out like a cascade and change even bigger things. Their presence changed the game even if it only happened in subtle ways.

That meant they had to make sure those ripples didn't cause any tsunamis.

Kon had warned them about a particularly dangerous moment, where Tris might wind up in trouble, and they opted to hang around and make sure it didn't lead to catastrophe.

So they tried their best to keep an eye on Tris and when it seemed the time had come, a night that Tris walked alone through the railed hallway next to the chasm, they waited nearby, peeking around the corner.

"I see 'em," said Raph, "at the other end. They're waiting to ambush her. I call dibs on dangling one over the pit. We can't both do it."