James Hancock has everything-a comfortable marriage, grown children who launched into their chosen careers, and the wealth and jet-setting lifestyle of a successful banker. He's a geeky slightly naive quant who's risen to the highest echelons of the cutthroat world of high finance on the strength of his prodigious mathematical abilities. But even with all the outward signs of personal and professional achievement, he feels an emptiness inside, a yearning for something more.

Then he's sent to London, where he meets Roxy Reid, a girl from the mean streets of the East End, the survivor of a tough childhood with a drug addict mother. Lost waif and formidable warrior, unschooled illiterate and genius savant, artless guttersnipe and sophisticated lady, childlike innocent and wise sage, with trusting immaturity and weary cynicism-Roxy is an impossible bundle of contradictions. She enters his life like a bolt of lightning, showing him in a flash how cold and sterile his life has been. Everything about her is wrong-she's far too young, totally alien to everything in his experience, and has long standing ties to organized crime. Drawn into her violent world of drugs and gangs, he must decide whether to risk everything to pursue her.