David Suchet narrates the BBC series featuring the Royal Navy's Hunter-Killer submarine, the HMC Splendid, on a top secret three-month mission. After travelling from its Farlane base to San Diego, the sub is charged with testing the first Tomahawk cruise missile, and the crew is followed every step of the way. Also included is a feature on the sub's new Lieutenant Commander as he undergoes the 'Perisher' selection course.