TV Guide for Now Tuesday 25 in Sky History 2

Military historian Stephen Bull tests the three most significant weapons of the sea and explores whether the subsonic torpedo could rule the waves in the future.

An exploration into the dark art of spy-craft reveals the deadliest weapons deployed to gather information and assassinate enemies.

Venture into the unknown stories of the American frontier and the anonymous Black figures that have inspired countless Hollywood tales, yet have been erased from the silver screen.

A look at cases where people have claimed strange voices urged them to commit horrific deeds. Could they have been obeying the orders of aliens.

Experts scrutinise prehistoric ruins, asking whether humans could have built these advanced structures alone. Might they have had alien help.

Few have ever heard of the top-secret base in the deserts of Utah known as Area 52, but reports of UFOs have convinced people that the US military is keeping secrets.

Sharp Top Mountain B-25 Crash: Garth Barnard investigates World War II air accidents, starting with a B-25 training crash in Virginia that killed five crew.

Explore the complex case of the death of Wladyslaw Sikorski, the Polish PM whose plane crashed soon after taking off in 1943.