The Timewatch strand returns with the story of how, in July 2007, 61 men and women set off on an extraordinary voyage to sail the world's largest reconstructed Viking ship from Denmark to Ireland. This film follows their seven-week journey and reveals the emotional and physical challenges the crew face as they cope with having less than a square metre each in which to work, live, eat and sleep - with no shelter from the weather. In their efforts to sail like the Vikings of old, the crew are pushed to the limit when they encounter larger waves and stronger winds than they've ever faced before.