Ethel Lina White

"Iris Carr is traveling 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...