Triumph turns to humiliation when a high-stakes take-down of a suspect goes awry. Andy McNally has made a critical rookie mistake, ruining a long-running undercover drug sting, and tries to make up for it by going face to face with a volatile gunman who already has one man's blood on his hands.

As the other rookies attempt to hunt down a violent escaped convict, Andy gets a lesson in the dangers of undercover work when she and her training officer, Detective Sam Swarek, search for a missing informant whose cover has been blown. Swarek's rogue tactics on the job aren't all that Andy finds troubling -- there's also a surprising, undeniable attraction between the two of them

While other rookies get ready to duke it out at the police department's annual "Fight Night" charity event, Andy wrestles with a dilemma of her own: Should she keep a promise to protect a domestic abuse victim who has been repeatedly let down by the system - even if it means breaking police protocol to do the right thing?

Andy goes under cover as a prostitute during a citywide sting operation; Dov and Andy's attempt to impress Sgt. Boyko backfires.

Andy and Traci are among the first responders to a home invasion at an upscale address; when the crisis appears to be over, Traci hurries away to handle a personal emergency; Andy must confront the armed suspect alone.

A fatal traffic accident may not be all that it seems and after Andy objects to how Callaghan handles a young murder witness, their romance may be headed for its own collision.

A heat wave makes life on the streets even more perilous for the rookies; the squad discovers that a serial rapist may be on the loose; during a blackout, Andy must take down a vicious predator alone.

Chris and Andy face a tough decision while investigating a vicious beating; Sam and Luke get competitive during a retraining exercise.

During the investigation of a highway accident, Chris and Gail find a license plate matches that of an Amber Alert. When disturbing secrets come to light after the parents are questioned, the entire division becomes involved in the search for the 9-year old girl.

During a routine prison transport, Andy and Sam's frustrations over their strained personal relationship come to a head when the inmate escapes. Dov and Gail search for clues to an amnesiac John Doe. Meanwhile, Detective Barber has Traci and Chris help him reconstruct some missing court case notes.

Andy and Sam look for proof that Andy's dad didn't committ a murder while he was blacked out from drinking. A masked vigilante steals Chris and Dov's squad car which in turn unintentionally helps a drug dealer.

Andy questions her future with the force; the rookies find out if they have passed their evaluations; an untimely arrest compromises a major drug bust; Andy goes under cover with Swarek.

Andy and Chris inadvertently compromise a major drug bust. Andy and Sam go undercover to try to salvage the operation but unfolding events put their lives in danger. Dov must chose between police work and his girlfriend Edie.