Captain Crane gives the date as July 14, 1978.
Ron Stein (Sailor)
Nelson and Kowalski have a confrontation with some of the bad guys, with Nelson lobbing a smoke bomb and shots being exchanged. After one of the men is shot, we see two others. One of them--a tall, thin, dark-haired man--is frequently seen playing background crew on the Seaview, making it look as though he's defected to the enemy.
Crane and two other men go to the radiation chamber to try to shut things down. They leave the outer door open while they open the door leading directly to the chamber, which means that radiation will get out that much faster. Meanwhile, the saboteur comes into the outer chamber and rips up a panel while standing right next to the open door of the radiation chamber, risking both getting caught and radiation poisoning.
After Nelson and Kowalski are captured at the bookstore, Hobson shows up. He tells Lydia to remove Nelson's gadget that will transmit a signal if his heart stops beating. There is no explanation as to how Hobson knew about the gadget, because if he'd been eavesdropping on them at the time, he would have known about Nelson's suspicions and plans.
Crane: You know, the President took it very well. He says a man learns a great deal sitting on top of an armed nuclear bomb for twenty-four hours.
Nelson: I can think of a number of important people in this world of ours who would profit enormously from the same experience.