Episode 4
S2, E4: Severide wants to implicate the serial arsonist; Dawson and Shay face the unexpected on a routine call; suspicions indicate Clarke is the mole; Mouch campaigns for union president.

S2, E4: Severide wants to implicate the serial arsonist; Dawson and Shay face the unexpected on a routine call; suspicions indicate Clarke is the mole; Mouch campaigns for union president.