Caesar is too focused on his task to really notice what's going on behind him--or well, he stops noticing the second he notices that Zaknafein has gotten between him and the protal. Good. He felt like he could trust the other man.

And then there's screaming. Shit shit shit, they're coming through--

No more time to try to shut down the machine properly. Caesar slams his fist down on the big red button, bringing the entire thing to an abrupt halt, even though he knows it'll likely fry some of the components in the process.

The portal closes.

Right on the warrior as he's stumbling through.