In a universe where the laws of physics and the speed of light are completely alien to our own, the travellers on the ship Peerless have completed a generations-long struggle to develop advanced technology in a desperate attempt to save their home world. But as tensions mount over the risks of turning the ship around and starting the long voyage home, a new complication arises: the prospect of constructing a messaging system that will give the Peerless news of its own future.