The Girl in the Plain Brown Wrapper (1968) is the tenth novel in the Travis McGee

Travis McGee

Travis McGee is a fictional character, created by prolific American mystery writer John D. MacDonald. Unlike most detectives in crime fiction, McGee is neither a police officer nor a licensed private investigator; instead, he is a self-described "salvage consultant" who recovers others' property...

 series by John D. MacDonald

John D. MacDonald

John Dann MacDonald was an American crime and suspense novelist and short story writer.MacDonald was a prolific author of crime and suspense novels, many of them set in his adopted home of Florida...

. The plot focuses on McGee's investigation of a beautiful young woman who is mysteriously losing her mind without any apparent physical or mental disease. Along the way, he discovers various troubling facets to the small Florida town where she resides.