O Quinto Macaco is a Brazilian novel written by José Rodrigues dos Santos. The story follows a group of scientists who are conducting research on monkeys in the Amazon rainforest. They discover a mysterious virus that could potentially wipe out humanity.
As they try to contain the virus, they realize that there is a fifth monkey in their research group that could be the key to understanding and stopping the spread of the deadly disease. The race against time to find the fifth monkey and prevent a global pandemic becomes the central focus of the novel.
The novel explores themes of science, ethics, and the consequences of human actions on the environment. It is a gripping thriller that keeps readers on the edge of their seats as the characters navigate through the dangers of the rainforest and the complexities of the virus.