Not much might survive the subsequent apocalypse, but the newspaper itself shows up again, four episodes later, in ‘What You Need’. In this case, it’s the violent loser Renard who has the paper brought to him, hoping to use a mysterious fountain pen to divine the winners of the listed races.

The recurrence of the newspaper might be an in-joke by the programme’s makers, or just a handy reuse of a prop. As the latter episode continues into the evening, however, there’s no chance that the two episodes take place on the same day. (Unless Bemis is still carrying yesterday’s paper…)

Much of the film was shot in Spain, with the streets of Madrid redressed to become Moscow. So when the crowds of Spanish extras march through the streets singing the communist Internationale, they had good reason: they were living under the dictator Francisco Franco.

The secret police took a dim view of all this revolutionary singing and kept a close eye on the extras, while apparently some local residents also misunderstood the singing, and toasted the revolution.

The following letter regarding the dogs’ acting careers appeared in David McGillivray’s ‘Now You Know’ column in the magazine Films and Filming (June 1983), as a response to a reader enquiry:

My thanks to Michael Powell for passing on to me the following communication.

“Our names are Erik and Spangle and your letter has been dropped in on our celestial kennel by a passing astronaut. Our dear owner on earth was Mr Michael Powell, who had something to do with films – we never found exactly what. Erik is named for Erik the Red and Spangle’s name comes from a film in which Wallace Beery says to Jean Harlow ‘I don’t like all those spangles on your dress’, a remark which prompts Robert Benchley’s ‘I had a spangle once, a cocker spangle’. Mr Pressburger wrote us into the scripts of the films you mention, but the camera obscura scene was our own idea.

P.S. If you see Colonel Blimp again, watch when we arrive in the house in London Square. Erik was so excited that he cocked his leg on a piece of Chippendale.

(The film referred to is probably China Seas, which featured all three actors and was released in 1935, so about the right time to have inspired the name of a thespian dog working in the early forties.)

The escalator itself was made by Rowson and Clydesdale for the production, at a cost of £3,000 (in 1946 money). It featured 106 steps, each 20 feet wide, and was powered by a 12hp motor. The engineers who built it nicknamed it ‘Ethel’.

The shots of the harbour, and of the whole island during the ferry’s approach at the beginning, use Peddocks island in Boston Harbour (although even this has been enhanced in the shot above, with CGI adding higher mountains and cliffs than exist on the real island).

Peddocks Island was used by the US military as a harbour defence fort (‘Fort Andrews’) until after World War Two. There are several abandoned military buildings left over, and some of these are visible in the early shots of the characters’ arrival.

The island has camping and swimming facilities, although if you’ve seen the film, you may not be too keen on taking the family on a waterside holiday.