Goofs

On the zeppelin towards the end, a ladder that Oliver Reed climbs down has a naval type hatch door in the wide shot. The next shot where he is partly down the ladder there is no hatch door to be seen.

37:45 As Sonia and Ivan are inside the cabin on the Paris to Brussels train, the outdoor scenery has only buildings, the next frame is the country, and when they are in the dining car, they are along the river. After Ivan burns Popescu's face, Popescu uses the rear door to jump into the water which is impossible for a train to travel on without tracks.

When the heads of state gather at the castle, the Deutschlandlied plays for the German emperor. However, Deutschlandlied only became the national anthem of Germany in 1922. While Germany had no official national anthem before that, Heil Dir im Siegerkranz would have been the anthem used in the emperor's presence. However the tune for this is the same as the current British national anthem, so using it might have caused confusion to the modern ear.

General Von Pinck dies aboard the zeppelin from inhaling hydrogen gas after he accidentally slices through the gas bags with a sword. However, although in high concentration hydrogen can asphyxiate a person due to its capacity to displace oxygen, it is not toxic. Also, real hydrogen is invisible, and yet it looks like a greenish steam in the film.

While guns may spark, Ivan Dragomiloff (Oliver Reed) warns that a bullet, fired into a ballonet filled with hydrogen gas, will cause an explosion. A bullet per se won't work. They'd need an open flame, or sparks at least.

Twice, the gondolier sings after dumping a body in the water, but he sings in English not his native Italian.

Near the end of the film an English officer (Jeremy Lloyd) clearly shouts "Steady the butts" instead of "Steady the buffs." This phrase, which is used in J.B. Priestley's "An Inspector Calls," is reportedly linked to the "Buffs," the British 3rd Regiment of Foot (The East Kent Regiment).

When Sonya and Ivan are escaping the brothel in Paris, the champagne bottles they throw at their pursuers are clearly empty, break-away props. A real champagne bottle would burst, as the contents are under pressure, and spray foam everywhere.

Very obvious dummy that falls from the zeppelin at the end of the film.

When Ivan and Sonya begin their romantic intimacy on the bed, the top of her nylons are briefly visible. She had just finished a bath, and went from nude to wearing a towel. She'd never had the opportunity to put on nylons.

Obvious stunt double for Curd Jürgens in the wide shots of the fighting scene.

In the scene, about 40-45 minutes in, where Lord Bostwick visits General Van Pinck whilst the latter is at fencing practice, you will see a map of Europe on the wall. Although this film ostensibly takes place before World War I, the map is of post-Versailles Europe, c.1925-1939.

The film is set in 1914 and the British King character looks like Edward VII and is listed in the credits as Edward VII but Edward VII died in 1910. In 1914 the King was George V, this is an odd error for a film made in England. However, as the book was set in either 1908 or 1910, and the clothes are in line with Edwardian fashion, this would be correct.

The film is set in 1914, but Oliver Reed's hairstyle and sideburns are strictly 1968.

When Ivan Dragomiloff is poisoned, he knocks over the cup he drinks from onto the marble floor. The sound it makes is not of metal such as gold, maybe plastic.

It is never explained why Miss Winter thought The Assassination Bureau's chairman would agree to accept an assignment to assassinate himself rather than just killing her for knowing too much.

Ivan talks about a revelation similar to that experienced by St Paul in Tarsus. St Paul was originally from Tarsus, but had his famous revelation on the road to Damascus.

As the movie progresses, Oliver Reed's (Ivan Dragomiloff) sideburns change shape from scene to scene, even though the action takes place over a matter of a few days/weeks.