A ticket to oblivion

Summer, 1858. Young Imogen Burnhope and her maid Rhoda board a non-stop train to Oxford to visit Imogen's Aunt Cassandra, who waits at the terminus to greet them. All the passengers alight at Oxford, but the two women are nowhere to be seen. When he learns his daughter is missing, Sir Marcus Burnhope contacts Scotland Yard for help and Inspector Colbeck is assigned to the case.