While her brother, Ellis, and his friend try to find the Loch Ness monster in an attempt to get back into her father's good graces, Maddie is left on her own in World War II-era Scotland and experiences a social awakening.
In 1930, on the coast of Scotland, eight-year-old Kirstie finds a large egg which hatches into an unusual sea creature, and as he grows her family must decide what to do with him.