Set in Melbourne in 1928, Miss Phryne Fisher is going to Ballarat with her maid Dot. At night, Phryne wakes up and saves everyone in the first-class carriage as they are being poisoned with chloroform and smoke. An old lady is missing and her daughter is hurt. Moreover, at the station there is a girl who cannot remember anything, not even her name. Phryne is determined to find out who tried to kill everybody, where the old lady is, what has happened to the young girl and to protect her from further damage.