Now that Mills is cleared to return to squad, there's an open spot on Ambo 61.

Brett (Kara Killmer) is getting a new partner on Chicago Fire, but it's someone whom viewers are already very familiar with.

Now that Mills (Charlie Barnett) is cleared to return to squad, there's an opening for a paramedic on Ambo 61. However, that spot won't stay vacated for long. In The Hollywood Reporter's exclusive sneak peek from Tuesday's new episode, a familiar face swoops in to save the day and volunteers to work alongside Brett when they find out the latest paramedic scheduled in isn't up to snuff.

So who is Brett's new partner? And why are they already having second thoughts about the gig?

Take a look at the clip from "You Know Where to Find Me" below.

Chicago Fire airs Tuesdays at 10 p.m. on NBC.