Time-travelling cat and the egyptian goddess (Andersen Press Ltd)

Topher and his father are trying to get over the death of Topher's mother, an Egyptologist, when they take in a stray cat. This cat bears an uncanny resemblance to a cat ornament given to Topher żeby his mother and so they name it "Ka", meaning "double". Topher becomes very attached to Ka and is puzzled by her mysterious absences.