I'm not a fan of classic scifi and read very little of it so I have no idea how this novelette stacks up against others in the genre. The story follows Mackenzie, the commander of a star ship fleet which is shadowing the Isiur, some type of ultimate weapon. They're really not sure what it is, but it was built by the Draconians, a race bent on destruction for the fun of it. The Million Star forces have destroyed the Draconians at great cost. The Isiur is the last piece of Draconian resistance. Mackenzie fears attacking it might ignite a chain reaction that would destroy the universe. He's arguing this point with a delegation of the Million Star Council when a Xin named Metarion arrives. The Xin live extremely long lives and have assigned themselves the task of watching over the universe. Metarion recruits Mackenzie to take part in a bold plan to defuse the Isiur. The plan involves taking a Draconian prisoner to the Isiur and boarding it during a battle. Mackenzie has doubts about trusting Metarion. Is the Xin telling him everything? On whose side is the Xin?