The Annunciationist is the story of an American painter obsessed with the meaning and significance of paintings of the Annunciation. It is the intensity of the relationship between Archangel Gabriel and the Virgin, and the message conveyed, "You have in your womb an infant" that so fascinates Martin, our painter. He believes that Gabriel is somehow involved because before his announcement, the Virgin was a virgin. It is forbidden intimacy with the Virgin that so intrigues Martin because it had been what he had faced in his own life. The women he had been drawn to were women he believed were forbidden, and whenever consummation did seem to be a possibility, his sense of taboo stymied it.

With this obsession, Martin sets off to view Annunciation paintings in Europe. In the process, he finds models for his own paintings, which he makes in the course of his repeated returns to the Greek island of Santorini, which is his base in the villa of his friend Orlando Pettingill.

His travels take him to Assisi, Italy, where he has a relationship with a fallen-away nun, and a son is born as a result. Later he goes to an Eastern Orthodox Romanian monastery where he connects platonically with a young nun whose mother was murdered by Nicolae Ceau?escu, Romania's dictator. The nun becomes a participant in a painting of his. He connects with an American flutist, whose mother was a model for the sculptor Constantin Brâncu?i, and another child is born, and another Annunciation painting results.

Eventually, Martin finishes three Annunciation paintings populated by his models from his travels and his obsession. They are installed in a beautiful white stone gallery Orlando has built for them. There, his work looks out over the Aegean Sea, long after his own unexpected demise.