Ivan Canabrava is an insurance investigator of mysterious "deaths" involving a toxin of the frog bufo marinus which, when combined with a certain plant extract, induces catalepsy in humans simulating death--perfect for committing insurance fraud. After ten years of investigative work, Ivan writes novels from old case studies and becomes the famous author Gustavo Flavio. He begins an affair with the millionairess Delfina Delamare, wife of the director of his former insurance company. When Delfina is found dead in her car, the police declare a suicide, but Gustavo suspects foul play. Once and forever the detective, he is immersed in intricate plot developments that somehow connect to the frog's poison and surprising revelations.