In 1930s England, the lives of orphaned young Rowena and her aunt Miriam are changed by raising an abandoned seal pup, Laura, attracting the attention of naturalist Dr Bernard Lacey.
Orphaned Rowena arrives in Norfolk to stay with her Aunt Miriam. Miriam is shocked when Rowena rescues a seal pup after a hunter kills its mother.
Taking care of Laura the seal helps Miriam and Rowena to grow closer.
Naturalist Dr. Bernard Lacey stays at the cottage while studying geese on the marsh. Rowena takes a liking to him and - secretly - so does Miriam.
Miriam is caught off guard when Bernard asks if his fiancee Sylvia can stay with them.
Rowena prevents Bernard from leaving after Miriam misunderstands a show of affection. Rowena becomes lost in the notorious marsh mists.
Bernard has to make a difficult decision which results in strained relations at the cottage. A hint of mutual understanding develops between Rowena and Ted Yeoman.