The cataclysmic final book in the Blackwater Pond series. Brian, Tommy and Dave chase a broken hearted Cassie back into Aphelion Chiasm. They find that Nimbus, the bloodsucking red cloud, has all but taken over the kingdom. Old combatants must become new allies to give them a chance in deadly encounters with the forces of evil. However, Ebil feels it is caterpillars that will save them all. The Heart of the Swarm brings with it a new level of strategy, tension, and unexpected twists to the epic battle between good and evil. The future of two worlds may depend on the outcome.