?Chicago Fire Boss on Casey and Dawson's Big Decision, Severide's Upcoming Love Triangle

We're going to have a shocking ending around Episode 13 that's going to lead into 14, where 51 is never going to be the same. ...

[...] there's going to be a call that Casey goes on where he has to decide who he's going to save in a real Sophie's choice.

[...] it's going to be haunting, but it's also going to have ramifications that take up the next episode.

Chicago Fire returns with a two-hour crossover episode on Tuesday, Jan. 3 at 9/8c on NBC.