On 19 May 1941, the German battleship Bismarck slipped out of a Baltic harbor on its maiden voyage, Operation Rheinubung, tasked with cutting Britain's Atlantic supply lines. This first episode of a two-part History Hit series follows the Royal Navy's response, sending its finest ships, including HMS Hood, to intercept the sortie. The centerpiece is the Battle of Denmark Strait on 24 May 1941, where Bismarck and her escort Prinz Eugen, which carried its own film crew to document the operation, clash with Hood and Prince of Wales. Presenter Dan Snow talks through the engagement with naval historian Nick Hewitt, National Maritime Museum curator Andrew Choong, and Angus Konstam, author of a book on the hunt for Bismarck. The film draws on archival footage, ship diagrams, and expert analysis to reconstruct how Britain's most storied warship met its match in a single, brutal engagement. It sets up the chase that follows in the series' second part.