When Isabella, a factory owner, discovers an unconscious young woman on a pottery canal wharf she finds an accident has caused her to lose her memory. As Isabella tries to discover her identity, she meets a young canal boatwomen, Annie. Together they set out to discover the cause of Mary's accident.

Their investigations lead them to trace the whereabouts of a mysterious earthen pot which is somehow connected to Mary. However another sinister figure may be ahead of them in the search. Lawrence, Isabella's staid uncle is reluctantly drawn into the mystery. Can they solve the riddle of the pot and rescue Mary and her family.