Calema is a lovely, out-of-the-way planet on the verge of its own Age of Scientific Discovery. They have no idea they are on the rolls of the Protected Planets Ministry, or that alien species from all over the galaxy have their agents among them. Now a mysterious outside force has started interfering in Calema's development. And when the Most Valuable Substance in the Galaxy is discovered there, all the spies mobilize to get a piece of the action. But it is Timo, an agent for that newcomer species, the Humans, who might just save the planet--or ruin everything.