Ivan Sarnoff is poisoned at the prison cafeteria. The ambulance, taking him to Dade General is stopped and then t-boned by an SUV, forcing it into the path of an incoming train. Ivan, in extremely bad shape, somehow manages to escape, leaving behind the dead driver and dying police office. Horatio races on the scene but is too late. He thinks the Russians have tried to spring him from jail and knows that Gregor Kasparov is behind it. He goes to question Gregor and arrests Yelina Salas when she throws a drink in his face. Back at the station, Yelina, who was working undercover, fills in Horatio on Gregor's plan to steal back their gun shipment. Upon investigating the crime scene and finding one of the drivers and questioning him, the team very quickly realizes that the Russians were trying to kill Ivan instead of help him. Calleigh discovers that Delko's father, Alexander Sharova was in the van that hit the ambulance. Eric, knowing he's breaking the law, goes to his father and tries to get him to leave the Russian mafia and then lies to Calleigh about seeing him. Yelina is released back to the Russians but Gregor is suspicious of her and tells her if she doesn't kill Ivan she has to die instead. She manages to get a message to Horatio to let him know her cover's been blown and some intel about the Russians stealing their guns back from the armory. Ryan and Calleigh arrive on the scene to find the Russians already there. There is a huge shootout and to her shock, Calleigh sees Delko and his father in an oncoming car she's shooting at. Horatio is on the hunt for Yelina & finds Gregor bleeding on the floor. Ivan had already come through and took Yelina with him. Gregor shoots at Horatio but Horatio is too fast and kills him. He goes after Ivan, shoots and kills him and saves Yelina. Calleigh & Horatio get to the Everglades. The police units have already recovered the van full of guns. Alexander Sharova comes stumbling out of the brush, covered in blood. He tells them it's Eric's blood and he's hurt but doesn't know where he is. Together, Calleigh and Horatio have to search the Everglads for their beloved team member, a task almost too monumental to undertake.