Twelve-year-old orphan Malcolm McKenzie’s world is falling apart.

His mentor, clockmaker Jack Alexander, was found dead inside a locked clock tower.

His best friend — and Jack’s son — Peter is dying of a mysterious disease.

His only hope: a puzzle inside a seemingly broken pocket watch that even Jack couldn’t fix.

The watch, a precious heirloom passed down through a family of proud physicians, must be the key to solving Jack’s murder and a miracle cure for Peter. But shadowy figures stalk the streets of Edinburgh, scheming to steal the watch and its secrets for themselves. Malcolm, alongside pickpocket and fellow orphan Maddie, must outsmart and outrun their enemies to solve the watch’s puzzle and save the family that saved him … before Peter’s time runs out.