Kristell Thornell has taken this episode and spun a personal drama from it, centred on Agatha herself (using the name Teresa Neele) and a fellow guest at her hotel, Harry McKenna, who is nursing his own story of grief and guilt. On the Blue Train refers to the book Agatha was struggling to write at the time, but Thornell uses the image of the train as an effective metaphor, as Agatha muses on the idea of shifting from compartment to compartment, sitting with different companions,and playing with different identities.
On the Blue Train moves at a dreamy pace, chugging leisurely along and enjoying the scenery. There is a mystery of sorts about the fate of Harry's wife but this is not a mystery story or a thriller, so much as a psychological exploration of identity, betrayal, guilt and shame, lies and masks and degrees of trust. An interesting diversion.