Simon R. Green 
Guard Against Dishonor [EPUB ebook] 

There’s nothing safe about Haven, nor is there justice, truth, or honesty. The only thing stemming the forces of darkness from overtaking the city is the Guard, but even they are susceptible to bribes, threats, and general maliciousness. However, two members of the Guard hope to change that. Hawk and Fisher, the husband and wife team, are the only pure forces of good in Haven. They can’t be bought. They can’t stand for injustice. But they can kick your ass.For Hawk and Fisher, the job is about honor. But when their current case goes wrong, they face their most daunting challenge yet: working apart. Hawk has to investigate a powerful and lethal new drug while Fisher is delegated to policing a potential peace treaty talk, a suicide mission if ever there was one. Soon enough, the couple manages to find themselves in trouble, dishonored, and on the run. Even worse, a bounty has been placed on their heads, a bounty so large that even the nicest guy in Haven would kill them without blinking an eye. Is this the mission that’s finally too much for Hawk and Fisher?