Dexter finds Louis Greene's blood on his boat, confirming Louis is dead. LaGuerta tells Debra of her suspicions that the Bay Harbor Butcher is alive, and asks for Debra's help with the case. Isaak Sirko knows that Dexter killed Viktor Baskov and is out for revenge. Hannah McKay leads the police to the bodies of a couple killed by Wayne Randall, but Dexter realizes one of them was killed by Hannah. Isaak is arrested after a shoot-out at a Colombian bar and is brought in.