When the detectives investigate the sexual assault of the executive of a private military-contract company, they discover a larger conspiracy in Iraq.
Kenny joins Drew at his MMA veteran's support group; Jordan and Cain treat casualties from a hotel fire; Shannon uses her instincts to help save a young victim.
When a man is stabbed by an attacker dressed as the spirit of death, Danny investigates a voodoo community; Garrett tells Frank about a dark secret; Nicky and Erin take Jack and Sean trick-or-treating.
When two different people driving gas-guzzling vehicles are killed by a sniper, the city thinks a radical environmental serial killer is responsible; Danny's son is severely injured in a bicycle accident.
When Danny is pulled over because his car matches the description of one involved in a drug deal, police find cocaine in his trunk; Danny's family rallies to come to his defense.