Sept 1979 mass market paperback, Don Robertson (The Greatest Thing Since Sliced Bread: A Novel). In "Mystical Union", Robertson looks at the marriage of Barbara Sellers and Donald Pilgrim. There is no plot to speak of. The book is written in short chapters, skipping back and forth in time from the early 1900's to the 1970's. We hear from Barbara and Don and from their friends, lovers, and relatives as they consider their lives and the choices they've made. They think what might have been and they make peace with themselves and each other -- or not. The point is that they're thinking, and they're very perceptive - Pam Gearhart Amazon
Used availability for Don Robertson's Mystical Union