In The Water Horse: Legend of the Deep, Angus (Alex Etel) is a lonely, young boy who discovers an unusual egg on the side of Loch Ness in Scotland during the Second World War. The egg eventually hatches to reveal Crusoe, a mythical "Water Horse" who becomes Angus's treasured pet. However because of his ever increasing size and unusual nature plus the appearance of soldiers around the lake, Crusoe becomes ever more difficult to hide. The film details Angus's special and touching relationship with his unique Water Horse alongside his mother (Emily Watson) and the local handyman Lewis Mowbray (Ben Chaplin).