Night without end

An airplane crash lands on the Greenland ice cap far from its usual route after flying in a seemingly erratic fashion. A scientific research team based near the crash site rescues the surviving passengers and takes them to their station. The team finds that one passenger and most of the flight crew are dead with one of the pilots to be shot in the back. The only means of contact with the outside world, a radio set, is destroyed in a seemingly accidental manner.

With not enough food for everyone and no hope of rescue, the leader of the scientific research team, Dr Mason, decides that they must set out for the nearest settlement. Meanwhile the pilot who was shot and in a coma is found to have been suffocated. An attempt is also made on Dr.Mason life by getting him to be lost in the arctic night. The scientists suspicion falls on stewardess but she is soon cleared. Dr.Mason orders the radio operator, London, to stay behind and repair the radio so that a field expedition can be contacted. The dead passenger is determined to be a military courier and soon after that the wreck goes up in flames.

Dr.Mason leaves with the group along with the other scientist, Jackstraw while remaining in touch with their station by means on a short range radio. Meanwhile, the field expedition returns to the station and contacts Dr.Mason. They inform him that a massive military mobilization has happened to locate the crashed plane and that it carried something very important. The governments having refused to divulge anything have tried to contact Dr.Mason's station. Finding the station to be non-responding, they have requested the expedition chief, Captain Hillcrest to check out the station.

Dr.Mason decides to go on with the journey since any attempt to return will induce the murderers to act and keeps this new developments to himself and Jackstraw. Captain Hillcrest sets out after the group but soon finds that the petrol he picked up the station has been tampered with. Sugar has been added to the petrol causing the sugar to melt and stick to the engine parts leading him to get bogged down. A solution is found to this when on of the passengers, a chemist, suggests that the petrol be mixed with water and the top layer of the resultant mixture be siphoned off. Almost at the same time, the governments also relent and inform Dr.Mason through Captain Hillcrest that the military courier carried a top secret missile guidance mechanism and that it is made to look like a tape recorder. Dr.Mason realizes that one of the passengers picked up such a device at the crash site. But this precipitates the murderers into action and they take over the group.

Finding that killing the entire group is not feasible, the criminals make them ride with them. But soon they abandon all of them save the stewardess, for whom Mason has developed a soft corner, and the father of a passenger who is a boxer. In the process, one of passengers left behind is killed. The group stumbles on in the arctic blizzard guided by the guard dogs with one of them dying during this trek. Soon they come across the abandoned sled that contains rocket sondes. They use it to guide Captain Hillcrest to them and set out in chase across the arctic landscape.

They manage to catch up the criminals near the shore where a trawler waits for the criminals. But the intervention of navy, on information from Captain Hillcrest, frightens off the trawler. The criminals are surrounded here and after a bitter hand to hand combat between the protagonists and the criminals, the mechanism and the hostages are rescued.