Dragon Soul — J.B. McDonald

Everything was supposed to work out. They had the dragon under control, they were back with the mercenaries - things were supposed to be good now. That was the plan. Then word of plague in Katsu's country arrives, and with it knowledge that will shatter everything Ashe thought he knew about his lover.

When Katsu has to make a choice between Ashe or sailing overseas to a country that abandoned him to save a beloved sister -- Well, some choices are harder than others. Some are nearly impossible to make.