Inspector Jarrold

In the short story The Girl in the Train, Detective Inspector Jarrold is part of the Scotland Yard. He is in the hunt of Mardenberg, a spy and by coincidence his path crossed with that of George Rowland who had been asked by a girl on the train to Portsmouth to follow a man with a dark beard and light coat.

Portrayals
In the episode The Girl in the Train of The Agatha Christie Hour, a TV film adaptation of the story, the part of Jarrold is played by Ron Pember. In the story, it is not stated if Jarrold ultimately caught Mardenberg. In the adaptation he succeeds in arresting both the spy and his accomplice Betty Brighteyes with George's help. As George is leaving Portsmouth on a train, Jarrold even brings the prisoners to show George the "fruits of their victory".