Jesse Spencer previewed the upcoming season 2 arc for his character, Matthew Casey on NBC's Chicago Fire.
Read on for the spoilers:
"He goes away on a sabbatical; he takes a little time out.
But he's going to come back with a new lease on life." Although there won't be a new love interest in Casey's life, he will open himself up to new people in a slightly surprising way. "He becomes a family man. He's able to give something back to some kids. It's going to be an emotionally healing experience. The kids are going to help him, and it'll be a complicated, but nice, recovery."
Source: TV Guide