Bücher der Reihe The Four Horsemen

The underground world of Warlocks has always been under threat from the Saints, a fanatical government force. However, it is about to reach its tipping point. A Warlock has joined the Saints, providing them with the help they need to eradicate all Warlock presence. Jack Devlin, a Warlock mercenary, has been hired to track down this turncoat, but he can't do it alone. With the help of three other Warlocks Jack might have a chance to track down the traitor before too much damage is done to their world. If his team doesn't drive him insane first.