The novel intertwines the stories of a soldier in the trenches of WWI who appears to go mad and murder his superior officer, a vicious barbarian terrorising ancient Britain and a scientist in the year 2872 who is trying to perfect a wormhole generator as a means to interstellar travel. The main character, feeling he has wasted his life and has nothing to live for, kills himself then is approached by an old man he mistakenly identifies as God who wants him to take on three different missions through time to correct errors in the development of humanity. However, the experiment to create a wormhole generator inadvertently opens the doorway to another dimension with devastating consequences.