Strange things are happening, and Captain Marvel is pretty sure it has something to do with a certain crazy doctor! With the help of two sentient cockroaches, Dr. Sivana has recently escaped from Fawcett City Penitentiary and set out to take over the world. Using the one skill he has -- being a mad scientist -- Sivana creates a robotic mayhem on the city of Fawcett. But he needs more power, and it would appear that his archenemies Captain Marvel and Mary Marvel might be just what the doctor ordered.