Night without end

A BOAC 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 survivingpassengers and takes them to their station. The team finds one passenger and most of the flight crew are dead with one of the pilots having been shot in the back. The onthatly means of contact with theoutside 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 thatthey 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's life by getting him to be lost inthe 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 canbe 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 whileremaining 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 militarymobilization 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 thestation 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 themurderers to act and keeps this new development 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....