At sixteen Barrow joined a whaling expedition to Greenland. On his return he taught mathematics before accompanying Lord Macartney's expedition to China in 1792. In 1797, he travelled with Lord Macartney to South Africa on a diplomatic mission to settle the government of the new colony of the Cape of Good Hope. Barrow was appointed Second Secretary to the Admiralty in 1804. In this capacity he promoted British exploration, most notably of West Africa and the North Polar Region, with attempts to find a north-west passage from east to west through the Canadian Arctic.
Inspired by a true story, Invincible recounts the last 48 hours in the life of Marc-Antoine Bernier, a 14-year-old boy on a desperate quest for freedom.