At Christmas time, the Scotsman James and the Swede Danielle get to know each other at a hotel in Normandy – and fall in love. Their professional duties, however, set them apart again soon. The reputed engineer James has to travel to Somalia, the oceanographer Danielle returns to Greenland. They keep in touch via radio. Then, James is taken prisoner by Somali jihadists because he is, in fact, a special agent on a mission to locate a terrorist training camp. At the same time, Danielle is aboard a tiny submarine, submerging to the black depths of the ocean floor. They are both completely on their own but still their memory of the short but intense encounter in Normandy gives them the strength to endure these extreme situations.