“Suddenly,” he wrote in his more widely disseminated epistolary version of events, “we were off the rail, and beating the ground as the car of a half-emptied balloon might do. The old lady…” [We must read “Mrs Ternan” here] “… cried out, ‘My God!’ The young lady travelling with her [this is Ellen Ternan, of course] screamed.

“I caught hold of them both… and said: ‘We can’t help ourselves, but we can be quiet and composed. Pray don’t cry out!’

“The old lady immediately answered: ‘Thank you. Rely on me. Upon my soul I will be quiet.’ We were then all tilted down together in a corner of the carriage, and stopped.”

The carriage was indeed tilted steeply down and to the left. All baggage and loose objects had fallen down and to the left. For the rest of his life, Charles Dickens would suffer repeated spells of feeling as if “everything, all of my body, is tilted and falling down and to the left.”

Dickens continues his narrative:

“I said to the two women, ‘You may be sure that nothing worse can happen. Our danger must be over. Will you remain here, without stirring, while I get out the window?’ ”

Dickens, still lithe enough then at the age of fifty-three, despite his “frost-bitten foot” (as a long-time sufferer of gout, which has required me to partake of laudanum for many years, I know gout when I hear its symptoms, and Dickens’s “frostbite” was almost certainly gout), then clambered out, made the tricky jump from the carriage step to the railbed above the bridge, and reported seeing two guards running up and down in apparent confusion.

Dickens writes that he grabbed and stopped one of them, demanding of the man, “Look at me! Do stop an instant and look at me, and tell me whether you don’t know me.”