01/23/2013 (10:00PM - 11:00PM) (Wednesday) : CASEY IS PRESSURED TO COVER UP FOR A DRUNK DRIVER - When the drunk driver who hits a car and paralyzes a 16-year-old boy turns out to be the son of a dirty cop, Lieutenant Casey (Jesse Spencer) must decide whether or not to turn him in. Facing pressure and subsequent threats from the powerful and well-connected Detective Voight (guest star Jason Beghe), Casey decides to tell the truth, inviting a stand-off. Additionally, Severide (Taylor Kinney), who's fighting off the advances of the Chief's new assistant (guest star Meghann Fehy), learns he has a fractured vertebra in his neck that may never heal if he doesn't get treated, but ignores the doctor's advice so he can continue working. Meanwhile, Mills (Charlie Barnett) is torn between helping his mother at her restaurant and devoting himself full-time to the fire department, like his father did. Monica Raymund, Lauren German, David Eigenberg, Teri Reeves and Eamonn Walker also star.