A driver is disabled and killed by a sonic weapon. Park's new husband Peter is concerned about her odd behavior. Red has summoned Dembe. Raymond brings up the Havana Syndrome, then mentions the Americans have developed their own directed-energy energy weapon, which has gone missing. Its inventor, Dr. Benjamin Okara, has also disappeared. All of Okara's team is in hiding. A second scientist is killed at a motel by Okara. Harold decided to not turn himself in since the bullet that killed Doug Coster came from his weapon. Reddington's business associate Jovan is concerned about Dembe being in the FBI now. Ressler and Park find the dead scientist, just missing Okara. Detective Heber interrogates Harold about Coster's murder. The scientist left behind a disguised address on a notepad. Dembe and Park find another scientist at that address. The scientist tries to escape but is killed by the weapon, which affects Park as well. Dembe calls a shady old connection to order a chopper to evac her. Raymond blasts Dembe to crossing back over the line. Charlene has to confirm Harold's alibi with Heber. Reddington gets an address for Okara from a safe-rental operator. There's a hit put out on Dembe and Red has to decide if he should intercede. They locate Okara but he has set up a bomb in his van. Charlene backs up Harold's alibi. Okara says he wants to destroy the weapon along with anyone who could rebuild it. He is suffering from Havana Syndrome. He blows up the van and himself. A killer waits for Dembe, but Raymond shoots the assassin. Reddington wants Dembe to kill Jovan, who sent the hitman. Park doesn't have cancer but lost a baby she didn't know she was carrying. Weecha shoots Jovan instead. Charlene blames Harold because she had to lie.