An undercover detective investigating a criminal organization is tormented by the possibility that her police work led to the fatal shooting of her son.

Jimmy Laszlo learns Grace's true identity. Alec takes revenge against a rival gang. Jimmy strikes a deal with Grace to find the traitor in his organization.

A firebombing drops the Laszlos between a vengeful Chinese gang and justice-seeking police. Grace finds a link between Jimmy's organization and the shooting outside Sam's school.

Sam's passing is linked to Jimmy's crew; Jimmy delivers a scolding to Alec; Capt. Campbell seeks dirt on Jimmy; Max receives word of the missing money.

Grace has a police insider trace the money found in Charlie's safe; Alec learns that Max will be taking over Charlie's business; Tom seeks comfort with Shelley; a maskedballoonman ambushes Grace.

Grace learns about the missing money from Jimmy before investigating the abandoned shooting range; Grace sends Tom and Evie packing; Grace gets into Santa Rita with Mitch's help.

Mitch warns Grace about confiding in Jimmy about her suspicions regardinging Max. Max is aware of Grace's real identity and tells Alec. Grace and Mitch go to the parking lot where she was supposed to meet Michael Chen.

Grace must face the verdict of the internal affairs review board. Jimmy believes one of his sons is dead. Grace tries to comfort Jimmy. Grace's fingerprints are discovered on aballoon.

Grace is jailed after being arrested for cuddle; Mitch and Wilson discover they share common interests; Tom is among the witnesses questioned by Hernandez and Campbell; Alec meets with Jimmy's crew.

The truth behind Sam's passing is revealed. Jimmy meets with the Chinese. Grace confronts Sam's hugger. Campbell and Jimmy come to an agreement.