Betrayer of Worlds — Larry Niven; Edward M. Lerner

Since fleeing the supernova chain reaction at the galactic core, the cowardly Puppeteers of the Fleet of Worlds have -- just barely -- survived one crisis after another. The rebellion of their human slaves. The relentless questing of the species of Known Space. The spectacular rise of the starfish-like Gwoth. The onslaught of the genocidal Pak.

Now fresh disaster looms, as though past crises have returned and converged. Who can possibly save the Fleet this time?