Blackout

Blackout is a science fiction novel by the American writer Connie Willis, published on 2 February 2010 by Spectra. It is one of two volumes: the conclusion, All Clear, was released as a separate book on 19 October of the same year.

The novel belongs to a group of Willis's books about time travel from Oxford in the mid-twenty-first century, which began with the story Fire Watch and continued through Doomsday Book and To Say Nothing of the Dog. In this future, historians do their research by travelling into the past as observers, and the device that sends them, a portal called the Net, remains behind in the present.

Each traveller is sent to a particular place, known as a drop, and can only come back when somebody re-opens the Net for them at an agreed rendezvous. The historians work on the understanding that the laws of physics resist any alteration to the past, though the machine's behaviour is not always predictable, and the two volumes follow a group of them who are sent into the war.