Amanda Pitt is on a police major investigation team, trying to find the identity of a body found by the Forth and Clyde Canal in Maryhill. Martin McGregor runs a software company, and finds that someone is operating sophisticated credit-card skimming against one of his clients' customers. Out of curiosity, he pursues it, and finds something more complex than he imagined.
Their investigations become linked, and they reluctantly work together. Their only common ground is that Martin's secretary is Amanda's partner.
Meanwhile, a newspaper is investigating historic Glasgow gangster activity. The crime editor hires Dougie Green, who comes to the conclusion that Martin and Amanda were once involved with the gangsters.
Martin and Amanda need to follow through on their investigations while fending off Dougie. It won't be easy - this is personal for him.