Tim Whewell is in St Petersburg to meet the self-styled Russian nationalists and patriots who are volunteering to join the fighting in eastern Ukraine. He joins a group of volunteers as they undertake military training, and travels to Ukraine to see how the volunteer force is fighting on the ground.

From unexplained flashes in the night sky to flying saucers, this episode delves into the mysterious world of UFOs. How our drive to explain these bizarre phenomena, and desire to discover little green men, has in fact transformed our understanding of the universe

Follows the epic operation to secure, raise, and salvage the Costa Concordia cruise ship, which ran aground and tragically capsized off the coast of Italy on January 13th 2012, killing 32 people. The wreck stretches the length of three football fields, weighs 45,000 tons, and lies half submerged on the site of a protected reef, with a 160-foot-long hole in its hull. Moving it from its precarious perch on the edge of an underwater cliff will be a huge technical and logistical challenge. Joins a team of more than 500 divers and engineers working around the clock as they attempt the biggest ship recovery project in history.

Journalist and Youtuber Benjamin Cook hosts everyday people discussing a variety of attitudes towards sex. Tofu offers a 'honest, non-judgemental and entertaining view of sex and sexuality'

The self-proclaimed 'Islamic State' is a jihadi militia active in the north and east of Syria, and in the west of Iraq, which has shocked the world with its cinematic staging of horrific acts of violence and its unexpected advances towards statehood. But why could IS expand so rapidly?

A deconstruction of the Church of Scientology's claims through a combination of presenting a condensed history of Scientology and its founder, L. Ron Hubbard, how celebrities interact with the church, the stories of a number of ex-members, and the abuse and exploitation the ex-members described seeing and experiencing". The Church responded vehemently to the film, complaining to film critics about their reviews and denouncing the filmmakers and their interviewees. Directed by Alex Gibney, it is based on Lawrence Wright's book Going Clear: Scientology, Hollywood and the Prison of Belief (2013). Produced by HBO, the film premiered at the 2015 Sundance Film Festival