Humans have been forced by sheer numbers to migrate to a new galaxy with multiple habitable planets. Here, they find themselves surrounded by humanoid aliens, the Varangians, who thrive on extremely cold planets. Not direct competitors, the two races watch one another warily and after five hundred years agree on a mutually beneficial trade treaty. At first, all is well, but then three Varangians disappear in human territory. The Varangians turn to half-Varangian Commodore Nimrod Ekeroth, who heads the human environmental fleet. Now he must find out who is disappearing both Varangians and humans and troubling the alliance.