1. The Man with the Cardboard Box

People have called Dr Ittai Gradel a kind of Sherlock Holmes, if Holmes were Danish and obsessed with gems. He’s an antiquities dealer with an eye for stolen goods who will help unlock the mystery at the heart of this story.

When Katie meets him in London, he’s got something to show her - two ancient gemstones he believes belong to the British Museum.

But this whodunnit begins more than a decade ago as a man with a cardboard box wanders into an antiques market. He has some valuable treasure to sell.

Presenter: Katie Razzall

Producers: Darin Graham, Ben Henderson and Larissa Kennelly

Production Coordinator: Gemma Ashman

Mix and sound design : James Beard

Composer: Jenny Plant

Exec-producer: Joe Kent

Investigations Editor: Ed Campbell

Series Editor: Matt Willis

Commissioning Executive: Tracy Williams

Commissioning Editor: Dan Clarke

Archive: Sky News Australia