Following Shamima Begum’s route reveals a dangerous Islamic State group smuggling network, but that’s not all. A local taxi firm isn’t what it seems and a gangster threatens to make Josh “disappear.” It all ends in an underground carpark with a stack of secret documents and a warning.

Reporter: Josh Baker Written by: Josh Baker and Joe Kent Producers: Josh Baker, Sara Obeidat and Joe Kent Field producers: Hussam Hammoud and Zeynep Bilginsoy Composer: Firas Abou Fakher Theme music: Sam Slater and Gunni Tynes Mix and sound design: Tom Brignell Production coordinator: Janet Staples Series Editor: Jonathan Aspinwall Head of Long Form Audio: Emma Rippon Commissioning Executive: Dylan Haskins

This episode contains strong language.