On 6th November 1942 the S.S. City of Cairo was torpedoed by the German U-boat U-68 in the middle of the South Atlantic.

Nearly 300 men, women and children escaped in lifeboats as commander Karl-Friedrich Merten gloated to the captain of the Cairo, 'Goodnight, and sorry for sinking you', and pointed out how unlikely it was any of them would survive. What followed is one of the greatest tales of survival and endurance.

The Cairo's captain decided their only hope of survival was to sail 480 miles to Helena, despite the considerable chance of getting lost forever. The journey would take weeks and with water rationed to just 110ml a day despite the tropical heat, the survivors grew weak and the extremes of human nature - the depravity and the heroism - would reveal themselves. Things would get worse for them as the lifeboats separated and eventually lost contact with each other, and many died of thirst or exposure.