Touch Not the Cat is a novel by Mary Stewart, first published in 1976. Like many of Stewart's novels, the story has a supernatural element.
The heroine, Bryony, has the gift of telepathy, and is able to communicate subliminally with a man she regards as her lover, but whose identity she is unsure of. She knows that he is a blood relative, and assumes him to be one of her three male cousins, twins Emory and James, and the younger Francis.
Bryony returns to the UK having received a telepathic message and discovers that her father has been hit by a car, and has died after speaking some mysterious phrases.
She remains puzzled about the identity of her telepathic contact. Her initial preference is for James, but she gradually realises that the twins are plotting to steal her inheritance, and that her secret lover is a long-standing friend to whom she had not known she was related.
Bryony gradually solves her father's puzzles, some of which include a maze depicted on the family's arms, the motto being "Touch not the cat". In the book's climax, the twins attempt to murder Bryony and flood the family gardens, so they can sell them for redevelopment. They are stopped by Bryony's lover.