The Number of the Beast

by Robert A. Heinlein

The book is a series of diary entries primarily by each of the four main characters: Zebadiah "Zeb" John Carter, programmer Dejah Thoris "Deety" Burroughs Carter, her mathematics professor father Jacob Burroughs, and an off-campus socialite Hilda Corners. The names "Dejah Thoris," "Burroughs," and "Carter" are overt references to John Carter and Dejah Thoris, the protagonists of the Barsoom novels by Edgar Rice Burroughs.

In the opening, Deety is dancing with Zeb at a party at Hilda's mansion. Deety is trying to get Zeb to meet her father to discuss what she thinks is an article Zeb wrote about n-dimensional space, even going so far as to offer herself. Zeb figures out and explains to Deety that he is not the one who wrote the article but a relative with a similar name.

After dancing a very intimate tango, Zeb jokingly suggests the dance was so strong they should get married, and Deety agrees. Zeb is taken aback but then accepts. As they are leaving, Deety and Zeb rescue Jacob from a heated argument he is having with another faculty member before a fight breaks out. As they are approaching their vehicles, Hilda comes out, deciding to tag along. Zeb, having a premonition, grabs the three of them and ducks behind another vehicle before Jacob and Deety's vehicle explodes. Zeb gets everyone into his modified air car Gay Deceiver and by activating the Deceiver's flying capability, escapes undetected by the authorities or the criminals who put a bomb in the other vehicle.

Zeb flies to Elko, Nevada, the state being the only one to allow people to get married 24 hours a day with no waiting period or blood test. The incidents have so traumatized Jacob that he has agreed to marry Hilda and so they have a double ceremony. The couples then go to Jacob's hidden cabin in the woods, where they have their honeymoons.

Thus begins the series of adventures that the four embark upon as they travel in the Gay Deceiver, which is equipped with the professor's "continua" device and armed by the Australian Defence Force. The continua device was built by Professor Burroughs while he was formulating his theories on n-dimensional British and Russian Empires, but near the end of the novel, Heinlein's recurring character Lazarus Long hints that they had traveled to Barsoom and that its "colonial" status was an illusion imposed on them by the telepathically adept Barsoomians:

Title

In the novel, the biblical number of the beast turns out to be not 666 but $(6^6)^6$ or 10,314,424,798,490,535,546,171,949,056, the initial number of parallel universes accessible through the continua device. It is later theorized by the character Jacob that the number may be merely the instantly accessible universes from a given location and that there is a larger structure that implies an infinite number of universes.