Son of Rosemary is a 1997 horror novel by Ira Levin, and is the sequel to Rosemary's Baby.
The novel begins in November 1999 with Rosemary Woodhouse waking up in a long-term care facility, where she has lain in a coma since 1973. Wholly unharmed, Rosemary soon learns that her coma was the result of a spell cast on her by the coven when they discovered that she ran away with young Andy. In her absence, Andy was raised by Minnie and Roman Castevet, the leaders of the coven. Rosemary recovered only after the last member of the coven died.
Rosemary finds that her son Andy, now thirty-six years old, is the popular and charismatic leader of an international charitable organization. Mother and son are reunited, and Rosemary instantly becomes world-famous both for her remarkable recovery and as Andy's long-lost mother. Rosemary is also struck and puzzled by a repeated reference to "roast mules," an anagram that many people keep bringing up.
Andy assures that he has rebelled against the coven's evil influence and now uses his powers to achieve world peace, but a long chain of deadly events leads Rosemary to believe that her son has unwittingly become the Antichrist and is ushering in the end of the world. Her fears are proven correct when a candle-lighting event Andy has organized to celebrate the new millennium unleashes a deadly virus that destroys all human life. In the wake of the destruction, Satan returns to earth and drags Rosemary to Hell.
Rosemary abruptly wakes to find that it is 1965 again and she is still married to Guy Woodhouse. The events of the entire first book and nearly all of the sequel have been a vivid dream of Rosemary's. Rosemary and Guy receive a call from Rosemary's friend Edward Hutchins, who offers the couple a rent-free apartment in the Dakota Apartments (the model for the Bramford, their building in the first book) for a year. The couple is delighted at the offer until Hutchins makes a remark about lighting candles and "roast mules" that causes Rosemary to regard her dream as a warning.
The book contains the anagram puzzle "roast mules." Levin never gives the answer, simply saying that it is a word that most five-year-old children would recognize. The only one-word English solution is "somersault". Among the hundreds of two and three word solutions are "soul-master", "tamer souls", and "almost sure".