It is the turn of the twentieth century and a British astronomer, Thayer, high on Darwin and other progressive scientists of the age, arrives in Egypt to embark on the project of a lifetime: the excavation of a triangle in the desert, with sides hundreds of miles long, to be filled with petrol and set alight. The purpose: to send out a signal to life on Mars (for which he has evidence) that humans exist. But as work progresses, the huge task force of Egyptian workers is struck by disease and rebellion, and the success of Thayer`s project looks increasingly uncertain.