Charlie Stross' latest novel Halting State is an off-beat high-tech thriller built around computer games of many kinds.

It is set in near-future Edinburgh, Scotland, but the million-dollar bank robbery that starts the action happens on the island of Valiant Dreams in the online game Avalon Four.

At first, Halting State looks like a police procedural. In a text full of police slang and Scottish dialect, Detective Sergeant Smith tells of being pulled off her routine day dealing with serial B&Es in Edinburgh, and dispatched to a former nuclear bunker where a theft has been reported by someone raving about orcs and dragons.

Sue Smith is not your usual hardboiled detective; she is "one of the few overtly heterosexually-challenged sergeants in C division", with a witty turn of phrase. She's stunned when people from Hayek Associates show her video of a band of orcs marching into their virtual bank and stealing treasure from safety-deposit boxes.

As Sue puts it, "collaring nerds for breaking and entering is one thing, managing the gay community outreach program is another, but international cybercrime in a nuclear bunker under Drum Brae is right off the map."

Although the stolen treasure existed only in the virtual world, the theft will nonetheless have serious financial repercussions. Hayek Associates is a high-tech startup company which runs virtual banks for massively multiplayer online games, stabilising the economies of various imaginary realms; if word leaked out, the company could lose tens of millions of Euros.

Sue is joined in her quest to solve the crime by two equally offbeat characters sent by an insurance company trying to minimise its potential losses from the robbery: Elaine, a forensic accountant who looks like a librarian but wields a sword like a mediaeval German warrior in live action real-time role-playing games; and Jack, a virtuoso games programmer with a highly charged sense of guilt.

The author, Charles Stross, has some serious computing expertise, and his data-saturated future Scotland is thoroughly convincing. Computer games of all sorts are everywhere. As well as the wildly popular multiplayer games such as Avalon Four, millions of people play Alternate Reality Games such as SPOOKS, which puts an espionage overlay on everyday life.

But just as a robbery in Avalon Four creates serious real world money issues, important people have been playing some very strange games, and lives are at risk.