Here's the official guide of Chicago Fire episode 20 "Ambition". This episode airs on Wednesday, April 4th on NBC.
MILLS’ DRIVE TO JOIN SQUAD CREATES FRICTION WITHIN THE FIREHOUSE—
- Mills (Charlie Barnett) finds himself the target of resentment from some colleagues when Severide (Taylor Kinney) supports his desire to join Squad.
- Tara (guest star Brooke Nevin), a paramedic candidate, joins Dawson (Monica Raymund) and Shay (Lauren German) on the job for a few shifts.
- Meanwhile, Shay comes to the aid of Cindy Herrmann (guest star Robyn Coffin), who suffers from pregnancy complications while her husband Christopher (David Eigenberg) is out of town.
- Elsewhere, Dawson and Casey (Jesse Spencer) draw closer as the grand opening of Molly’s draws near, and Casey receives a surprise visit.