Goofs

Early on in the film a scientist commits suicide by jumping off a moving train. According to the direction of the train, he jumps out on the right hand side. However, when the train is stopped and people disembark and go down the line to check on him, they are getting out of the train on the left hand side.

The train pulls out of the station in daylight pulled by engine no 6015. By freeze framing a night shot, just after that of the train passing a signal box it can be seen that the engine has smoke deflectors, which 6015 did't have. There's then a scene in a carriage and one can see through the window that it's daylight then a night shot of Major Hall in a carriage although there are some glimpses of daylight seen through the window.

The communication chord is pulled and the professor jumps from the train but a shot of the engine shows that it's is now numbered 5056.

At Paddington Station Professor Sharpey is met on the platform by Dr Tate. The carriages alongside them are all maroon but they get into a two tone coloured carriage. Major Hall, who's been following them gets into a one coloured carriage.

When watching the 'Isolation' cine film which is supposed to be a documentary recording of a trip to rescue a French scientist. It starts off as a single camera filming the situation moving to show what is going on with the action. But when talking to the scientist reaction shots of the two other men are cut in now suggesting that this is now a three camera setup.