Touch not the Cat

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.