This thriller is set in 1958, with backdrop the first successful launching of a US satellite. Several of the characters are mathematicians turned rocket scientists. They frequently muse rather explicitly over elementary number theory. The main character, who has lost his memory, begins to figure out his past when he finds a number theory textbook in a library.

The fact they did major in math at Harvard was only a backround for Follett was writing a story about scientists. Math is not really a part of the story but is brought up several times just to show that they can be in this line of work and was just made more realistic.