How does Kestner escape Spectrum Hall in the novel, The Last Wild?

Kester dreams that 100 pigeons have broken into his window and are telling him that he has special powers that can save them all. He talks to them and is shocked because he has not spoken since his mother’s passing. When he wakes up from the dream, he finds a hoard of cockroaches on his floor, including their leader, The General. The General tells Kester that he must follow them to save the world. They lead Kester out of his room and escape through an underground tunnel that lets out on the edge of the island near the cliffs overlooking the polluted ocean.