Blackout and All Clear are the two volumes that constitute a 2010 science fiction novel by American author Connie Willis. Blackout was published February 2, 2010 by Spectra. The second part, the conclusion All Clear, was released as a separate book on October 19, 2010. The volumes won the 2010 Nebula Award for Best Novel, the 2011 Locus Award for Best Science Fiction Novel, and the 2011 Hugo Award for Best Novel. These two volumes are the most recent of four books and a short story that Willis has written involving time travel from Oxford during the mid-21st century, all of which won multiple awards.

Plot introduction Willis imagines a near future (first introduced in her 1982 story "Fire Watch" and featured in two of her previous novels: Doomsday Book and To Say Nothing of the Dog) in which historians conduct field work by traveling into the past as observers. The research is mainly conducted at the University of Oxford in England in the mid-21st century. In their world, time-travel has been known since the early 21st century. The time-travel device, a portal called "the Net", remains in the time-traveler's present, while sending the time-traveler to a particular location (called "the drop") and time. They can return from the same location when someone in the future re-opens the Net for them at an agreed-upon "rendezvous" time.

Historians in Willis's world believe that the laws of physics resist possible alterations to the past by preventing time-travel to certain places or times. In some cases, the machine used for time-travel will refuse to function, rendering the trip impossible. In other cases, "slippage"—a shift from the exact, desired target in time and/or space—occurs. The time-traveler arrives at the nearest place and time suitable for preventing a time paradox; although sometimes this is only a few minutes later than planned, it can be as much as several years. An example is when the character Polly wishes to arrive on September 10, 1940, in London, but instead arrives on September 14.

In addition to slippage, which the technicians operating the net cannot control or predict, there are other reasons why a historian might not be able to travel to a certain time. Once a time-traveler has visited a certain date, he or she can never go to that same time again. The 21st-century authorities controlling time-travel also have rules and can deem some historical periods too dangerous for time-travel, even though those times might be theoretically accessible.

Plot summary

Blackout It is the year 2060, and the historians (time-traveling research staff) at Oxford University are a hair's breadth away from revolting. Mr. Dunworthy keeps changing their assignments at the last minute, for reasons not explained until All Clear. Michael Davies, who had prepared for a first-hand look at the events of Pearl Harbor, for example by having brain implants to give him an American accent and knowledge of that time, abruptly finds himself instead being sent to witness the response to the Battle of Dunkirk. The constant changes also mean that the wardrobe department cannot assemble the proper wardrobe for Polly Churchill, who plans to work as a shopgirl during the Blitz. Merope Ward, overseeing child refugees from London in Warwickshire, finds herself utterly unable to find the support she needs to complete her first assignment in the past. Dunworthy himself is nowhere to be found, having set off for a meeting with another academic, Ishiwaka, who theorizes that continued time travel has pushed the laws that safely govern it to the breaking point.

When they make it to World War II-era England, all initially seems well.

Merope takes on the persona of an Irish girl, Eileen O'Reilly, to secure a position in the staff of an English country manor house. From December, 1939, to May, 1940, she works for Lady Caroline as a servant; she desires to observe children evacuated from London during World War II.Willis, Blackout, p. 43. She sees far more of these children and their predicaments than she bargained for, especially some undisciplined trouble-makers, sister and brother street urchins Binnie and Alf Hodbin. Merope, referred to mostly in both books as Eileen, excels at her assignment, even when she comes to dislike it and to try desperately to escape to her "drop," which is located in the woods outside the manor grounds. The children love her, and when Alf comes down with measles, and then infects the dozens of other children, the house is quarantined; Eileen proves an excellent and tireless nurse, against her own wishes. She is appalled by what she considers the barbaric medical treatments of 1940 (she errs by referring to "a virus," a term not generally known then), and manages to save Binnie's life only by stealing some aspirin to bring the girl's fever down.

Eileen repeatedly finds herself unable to return to 2060 via her drop. She helps to return most of the children to their homes, and then plans to travel by train to seek help from her friend Polly, who should, by September, 1940, be a shopgirl in London. To her dismay, the local vicar, Mr. Goode, has arranged for Binnie and Alf to be given "safe passage" to Canada, so that they will not have to remain with their neglectful mother in Whitechapel, which, as Eileen knows, was bombed during the Blitz. But, as she also knows, they are likely to be transported on the SS City of Benares, which was torpedoed by a German submarine. Unable to allow this to happen, Eileen accompanies the brats to London, after which she can seek Polly. During their train trip, Alf's mischievousness delays their train; if the train had proceeded on time, it would have been destroyed by German bombers. When they disembark from the train and cross a field to find a bus, they witness in the sky the beginning of the Battle of Britain. Alf (who fancies himself a plane spotter) and Binnie are delighted to watch an air battle between a German Messerschmitt fighter plane against a Hawker Hurricane and a Spitfire. The Messerschmitt is destroyed, and Eileen manages both to return the children to their home and to find Polly.

Polly, fair-haired and pretty, secures employment at a department store in Oxford Street in the West End of London. Her intention (that is, her research assignment) was "to observe shelterers in the tube stations",Willis, Blackout, p. 172. but she ends up joining a group huddling under St. George's Church. The group, most of whom become fond of Polly, includes the nasty-tempered Mrs. Rickett, who owns a boarding house where Polly rents a tiny room; some other boarders, including the sweet but flighty spinster Miss Laburnum; Sir Godfrey, a Shakespearean actor who forms a crush on Polly; a rector; Mr. Simms and his dog Nelson; Lila and Viv, young women who chat constantly about dances and movie stars; and others.

Michael Davies had planned to travel to witness the attack on Pearl Harbor. Instead, he is sent to Dover, a trip he had intended to make later, where he had planned to witness heroism during the Dunkirk evacuation. When he discovers that, instead of Dover, he has landed in Saltram-on-Sea, a town 30 miles south, with his "drop" within some rocks on the beach, he tells the locals that he is Mike Davis, an American war correspondent, who wishes to cover the British anti-invasion preparations of World War II. The residents are pleased to find a "Yankee" interested in them.

To his horror, he is brought against his will onto the small, barely seaworthy craft Lady Jane of Commander Harold and taken across the English Channel to help evacuate the soldiers from the beach at Dunkirk. When they arrive at the mole there, soldiers begin scrambling onto the boat, but Michael must dive underwater to free the propeller from a corpse which has become entangled with it. Michael frees the boat and joins the evacuees on the deck, which is too crowded for movement, and the Commander guides the boat back to England. During the trip, Michael goes into shock and barely hears a rescued soldier, Private Hardy, thanking him for saving his life. When they return, Michael finds his right foot has been mangled. (He will limp for the rest of his life.) He awakes in Orpington War Emergency Hospital, where he is adored as a hero, but, for months, he is terrified that he has changed the course of history by saving soldiers.

Eventually, Merope, Polly and Michael meet each other in London. They are all worried because they cannot find drops which will return them to Oxford.

All Clear All Clear begins where Blackout left off, with Michael Davies (posing as an American journalist, Mike Davis), Polly Churchill (as Polly Sebastian), and Merope Ward (posing as Eileen O'Reilly) trapped in 1940 Britain during the Blitz. Just as in Blackout, the novel switches between multiple people and times.

As the novel opens, Polly Churchill, who is posing as a shop assistant, realizes that she has a deadline. She had already visited Oxford and London in 1943. Since she was able to do that, and she now believes she is trapped in 1940, she must either have returned to the future or died by 1943. She is convinced that she will in fact die. We later learn that Mary, a seemingly unrelated character whose experiences as a volunteer nurse and ambulance driver in 1943-44 are included in All Clear, is actually also Polly, under an assumed name (Polly being a nickname for Mary). Meanwhile, Merope and Michael have found Polly after discovering that their drops are also unable to return them to the future. Now together, the three believe that their own actions, particularly in Mike's case, may have changed the future so that there is no time travel, and that possibly it will involve Germany winning the war.

Knowing something has gone wrong which prevents them from returning to 2060 Oxford, the three time travelers attempt to determine an escape plan, but none of their efforts are successful. A fellow student, Gerald Phipps, who was supposed to be at Bletchley Park studying Ultra, never came through to his assignment. They realize that another Oxford historian, John Bartholomew, is also in their place and time, but understand this only less than a day before he will leave. (Bartholomew's time travel experience is the subject of Willis's short story "Fire Watch," written almost thirty years previously.) Frantically they try to get to him, but the three are separated and repeatedly delayed, not helped by the fact that this is the night of December 29, 1940, during which some of the worst raids of the war occurred. They are unable to find Bartholomew before he returns to 2054 Oxford. When Mike and Eileen figure out that Polly has a deadline in June 1943, and its implications, their search for a way out becomes even more desperate. Their frustration turns into tragedy when Mike is reported killed during a raid. Eileen refuses to accept his death, but upon realizing Alf and Binnie's mother has been dead for months, she volunteers to raise the orphans, thus giving her life, now trapped in the mid-20th century, a significant meaning. Polly fights with her about this, but Eileen is adamant and later proves to have become a very good mother to the children.