Richard Marino, LaSalle's old partner, gets shot while making an undercover drug buy. Rita got a job offer from the Department of Justice in Washington, D.C., but she doesn't want to leave her budding relationship with Pride. The team is trying to figure out how the seller, Nathan Kelly, was getting the drugs. The drugs Kelly had were supposedly in evidence at NOPD. LaSalle can't believe his old unit is involved. Gregorio and Sebastian go with the Coast Guard to intercept the drugs. Rita checks out Audubon Industries, which is buying up properties in Clearwater. Marino tells LaSalle the drugs were incinerated the previous week. Gregorio and Sebastian find an empty crate. Sebastian discovers there were many different types of drugs in the crate. Brian Cooper, Kelly's old high school friend, works in the NOPD Incinerator Room, but Pride and LaSalle find him dead in the incinerator. Rita got run off the road by a truck that had been following her and was injured. Sebastian and Gregorio find the drugs in the compost room and are attacked by a big man, who they take down. LaSalle and Pride arrest Marino for Cooper's murder. Gloves with Marino's DNA were found near Cooper's body, but he denies everything. Payments to the suspects were from Audubon Industries. Rita and Patten find a connection between Hamilton and Jordan Spencer. Aubrey and Spencer check out Marino from custody. Spencer shoots Aubrey, then takes Marino out of the car. Pride and LaSalle arrive and gunfire breaks out, with Marino shooting Spencer dead, before Pride can learn anything about Hamilton. Gregorio tells Sebastian she gave him allergy medicine. Rita tells Pride she's taking the job in Washington, D.C.