War at sea: a new form of warfare with exceptional challenges. In this episode, weapons expert Stephen Bull tests three significant weapons of the sea. The Byzantines guarded the Greek fire as the secret super weapon that kept Constantinople safe for over 800 years. Experts build an original replica for an experiment that will demonstrate the thunderous force of a ship cannon. One of the most devastating missiles ever invented is the torpedo, and a subsonic torpedo might be ruling sea battles in the future.

International experts test the catastrophic effects of the most destructive weapons that shaped the wars of the 20th century. Machine guns kill entire units within seconds, while the hand grenade has enormous power and can easily be carried in a backpack - but the most powerful war machine ever invented is the tank. Military scientists seek ever more demolition with least effort - does the Russian 'father of all bombs' finally reach all limits of conventional destruction?