The Sigma protocol

In Zurich, Switzerland, American investment banker Ben Hartman has arrived on holiday when he chances upon old friend Jimmy Cavanaugh -- a madman who's armed and programmed to assassinate. In a matter of minutes, six innocent bystanders -- and Cavanaugh -- are dead. But when his body vanishes, and his weapon mysteriously appears in Hartman's luggage, Hartman is plunged into an unfathomable nightmare, and suddenly finds himself on the run. Meanwhile in Washington, D.C., Anna Navarro, field agent for the Department of justice, has been asked to investigate the sudden -- seemingly unrelated --…