A good time slip story for younger readers which compliments others on this topic such as Devil's Mill (Unsworth) and Mill Girl by Sue Reid for older readers.Michael isn't happy about moving from his home in Nottingham to Cromford in Derbyshire, and especially the old mill worker house they seem to have moved to. He's sent out to occupy his time whilst his parents unpack, and buys an old cracked cotton bobbin (although he doesn't know that at the time) but it seems to have a life of its own, and whose initials FL are carved on the bottom? All is revealed when coming home from school one day he juggles the bobbin and finds himself back in mill worker days at the start of Arkwright's cotton mills in Cromford, and spends the day as a scavenger, picking up fluff and cotton waste from under the looms to cover for one of the boys of the family who live in his house. Desperate to get home, he finds his bobbin and manages to return home, having solved the mystery of FL and now having more understanding about life for a mill worker.