"Iris Carr is travelling across Europe by train when she unwittingly becomes embroiled in a sinister Balkan plot. Feeling disoriented after a fall, Iris is befriended by Miss Froy, an elderly English woman sharing her carriage. But when she wakes up from a few hours' sleep, Miss Froy has vanished without a trace. As fellow passengers claim the lady never existed, Iris faces danger and intrigue as she fights to discover the fate of Miss Froy-- and prove that she's not going crazy. Or is she?"--Container.

Based on the story "The wheel spins" by Ethel Lina White. Originally broadcast as a made-for-TV movie on BBC in 2012.