“Helicopter” - an activist yells. Then gun-wielding agents in balaclavas abseil down, onto the Greenpeace ship, to tow it to Russia.

This is the story of a campaign against oil drilling in the arctic that takes a dangerous turn. And the debate it sparks within the movement - should the organisers have better anticipated the risks of their campaign? Who is responsible for activists’ safety?

Presenter: Justin Rowlatt Producer: Alix Pickles Series Producer: Ellie House Editor: Matt Willis Sound Design and Mix: James Beard Production Coordinators: Maria Ogundele, Brenda Brown, Sabine Schereck Commissioning Editor: Dan Clarke

Archive: Prirazlomnaya Gazprom Oil Rig Protest in the Pechora Sea, Russian Investigative Committee, 18/9/2013 Other archive footage provided by Greenpeace