Ecdysiast (ek-'di-zE-"ast), n: one who or that which sheds its skin. It is late spring. Soon the 13-year periodical cicadas will emerge from underground by the millions, molt and fill the air with their joyous, deafening song. Above ground, 13-year-old Trygg Tolefson is struggling with his own emergence. Since the death of his older sister Katie, Trygg's parents have left him and his little sister Squirt to their own devices. When entomologist Allison Armstrong moves in next door, Trygg and she become fast friends. They decide to throw a neighborhood-wide cicada emergence party hoping to help Trygg's parents through their grief. Things begin to look up until Trygg learns his sister Katie meant to kill herself: she was in love with a girl whom Trygg's parents had forbidden her to see, got drunk, and drove her car into a tree. Devastated, Trygg goes to Allison's house for comfort only to catch Allison in a lie about her own personal life. Trygg rages at Allison who tries to explain that the choices his parents and Allison made, though disappointing, were the best they could do under the circumstances. As Trygg sheds his childhood skin by forgiving the people who have disappointed him, the cicadas begin to sing and the entire neighborhood emerges to witness.