Master Able Six finds a solution. Why not send along another Gunwharf Rat to keep him company? Able's grandmama, a Scot of wealth and influence, arranges for the two Rats to stay at her Edinburgh house, maintained by Esther Teague, a spinster.
Fellow Rat Avon March returns to Edinburgh with Davey. Adept at skulking, Avon will provide needed conversation, but also try to learn about the mysterious disappearance of a Royal Marine sergeant and Royal Navy warranted officer, from the hospital's famed Royal Infirmary.