Richard Scarry's Christmas MiceBook - 1965
Deb Solomon is a new mom suffering a spate of postpartum depression, a listless marriage and a career in free-fall. So she jumps at the chance to go to work in another world: a university laboratory housing language-competent apes and the humans who study and care for them, led by a brilliant primatologist Soraya Baldwin-Ruhl. But Soraya's star is already falling, and the people at the lab act more apelike even as the apes start to seem more human. Deb's own life becomes more and more a science-y soap opera as she follows Soraya into near-madness, then comes close to losing her life inside an ape cage.