While walking along a Paris street, Englishman Robert Stevens is shot by an unknown assailant, but luckily he is only struck glancingly and rendered unconscious.

André informs him that "Mademoiselle" is concerned that this shooting incident may bring unwanted police notice and end his usefulness.

An encounter with a policeman over a parking ticket reveals that she is Diane de Geurmantes and she believes him to be her chauffeur, Barnes.

After dinner, Diane retires, leaving the aged General de Guermantes, Victor and a British liaison officer to discuss military matters.

The next day, the general is taken for an inspection of an extensive secret underground military facility that Lanson is desperate to locate.

After the wreckage of Robert's aeroplane and a charred, unidentified body are reported in the newspaper as having been found, Lanson goes to see Sir James.

The latter has been warned by British military intelligence to pretend the body is that of his son, but Lanson suspects otherwise and sets a trap, sending a telegram to the chateau addressed to Robert Stevens, telling him to meet his father.

With the information obtained from the film, Lanson decides to plant a bomb on the nightly ammunition train to destroy the installation.