In addition to Spalding the crew consists of navigator Lenny Wilby, young second officer Hobie Wheeler, first officer Dan Roman, and Captain Sullivan. Sullivan is a competent and skilled pilot but is currently- and secretly- experiencing self-doubt in his abilities and career choice despite (or maybe because of) his many hours of flying. He also resents having Dan Roman as his first officer. Dan is quite a bit older than Sullivan and used to be a captain himself until a plane he was piloting crashed- through no fault of his own- killing quite a few people including his wife and son. Roman survived, but was left with a bad limp and an inability to return to the captain's chair, despite having forgotten more about flying than most pilots ever know. Having a first officer who is his senior in both years and experience makes Sullivan uncomfortable, especially given his present lack of self confidence.
Jose Locota is a fisherman who is flying for the first time, and he is keeping a suspicious eye on the twitchy passenger, Humphrey Agnew. His behaviour reminds Locota of a man he once saw knife another on a fishing boat. His reading of Agnew is pretty accurate; he took this flight because his wife's former boss- Ken Childs- is on it and Agnew is convinced that they're having an affair. Eaten up with jealous rage, he has a gun hidden away and intends to confront and kill Childs.
Meanwhile in the cockpit, the flight is proceeding as normal although Dan Roman has a momentary conviction that something is a bit off, though it's just a feeling because all of the instruments are reading exactly what they should. Sullivan, taking a break and resting on his cot experiences the feeling that the propellers are not perfectly in alignment. He returns to the cockpit to check, but just as Dan found, all of the readings are perfect. In the galley, a sudden strange vibration causes Spalding to spill hot coffee and burn her hand. She goes forward to the cockpit to report it, but the flight crew felt it as well and are checking over everything to try to find out what caused it. They can't find anything wrong. As they are running through the checklist of possible problems, Lenny reports that they've just passed the point of no return: it's now further to go back to Honolulu than to go on to San Francisco.