Steve Punt turns private investigator, re-opening his casebook of curious assignments. Steve examines the curious case of Argleton, the place that only exists on internet maps.

Steve Punt turns super sleuth, once again taking possession of the keys to Radio 4's very own detective bureau, bringing mystery and intrigue back to Saturday mornings.

In the first programme, Punt looks into the phantom settlement of Argleton. Search the web for this quintessentially English placename and internet maps show that it lies just outside the town of Ormskirk in Lancashire. But when our super sleuth travels to locate it on the ground, all he finds is an empty field. It turns out that Argleton doesn't actually exist.

Punt sets out to crack the mystery of how a non-existent place can appear in online maps. From the Domesday Book to Google Headquarters, Punt's quest takes him through a thousand years of history and into the murky world of plagiarism. He questions all the key players - and as he zeroes in on the truth discovers that in the cartographic realm nothing is quite as it seems.

Also in this series, Punt travels to the Polish-Czech border to investigate one man's theory that the Nazis had developed flying saucer technology. And he scrutinises a wax cylinder which is reputed to carry the only recording of Queen Victoria's voice.

Producer: Laurence Grissell.

Episode 2—Series 3