Sheldon Rhodes, an engineer developing a new guidance-missile destroyer, is blown up. Sam and Callen check out the wreckage, while Deeks and Kensi go to Rhodes' employer. Hetty sends Sam and Callen on a flight to Tokyo, to track a suspect, Aiden Tinker. One obstacle is that they can't take guns with them. Kensi and Deeks meet with Sam's SEAL buddy, Lincoln Stern, about the explosives used in the murder. Callen finds a dead flight attendant in the lavatory, then AIr Marshal Miguel Salazar sneaks up on him. Sam disarms Salazar, then they join forces. Deeks and Kensi find out the explosives were stolen. Sam and Callen tell the captain to turn around the plane back to L.A. One of the men who stole the explosives is on Sam and Callen's plane. Eric and Nell figure out there are four extra people on the flight, thanks to a hacked ticket scanner. The extra passengers are holding TInker hostage in the cargo hold, and one of them shoots Salazar, then Callen is in a shootout with them. They get Salazar upstairs, then find the second air marshal, Vanessa Barley. Deeks and Kensi track down Aric Webber, one of the hitmen, but Kensi shoots him after he takes a hostage. Eric figures out there's a virus built in the stolen file, but they need to shut down the wi-fi to keep them from being transmitted. Callen and Sam take out two of the extra passengers, but a third has Tinker as hostage. Sam has the captain tip the plane, then Callen subdues the hitman from above. Then they take out the fourth man trying to transmit the data. The Japanese figure out that the Chinese were trying to steal the plans.