The Hammer — K.J. Parker

Gignomai is the youngest brother in the current generation of met'Oc, a once-noble family exiled on an island for their role in a vaguely remembered civil war.

An uneasy peace exists on the island. The met'Oc are tolerated, in spite of occasional cattle stealing raids, only because they possess the weapons considered necessary protection against the island's savages. In turn, the locals are tolerated only because the met'Oc are too proud to talk to them.

Gignomai is about to discover what it means to defy his family. He is the hammer who will provide the spark that could ignite a brutal and bloody war.