The troubles with time travel in Connie Willis' All Clear

The second half of Connie Willis' World War II epic, All Clear, concludes the adventures of four time-traveling historians trapped in Blitz-era London. The historical detail is fabulous, but the time travel not so much.

All Clear concludes Willis' epic war adventure that began with Blackout. It is not a standalone novel by any means, and you'll want to read it directly after finishing Blackout: One of the joys of Willis' writing is the slow burn, the narrative that starts slowly with almost encyclopedic detail and gradually builds to a mesmerizing, intense conclusion that depends entirely on how deep involvement with the novel over the extended time that it takes to read. Certainly that was the case with The Doomsday Book, her previous novel about a time-traveling historian who gets trapped in the past. Like that book, All Clear delivers an emotional punch that can only come from getting to know characters over time, seeing their lost-to-time world in such detail that you really feel like you're there. Or that you've lost a friend if any characters meet a tragic end.

While Blackout took us into the countryside where children were evacuated, and into the rescue effort at Dunkirk, All Clear takes place almost entirely in London. We get to know the train station shelters where city dwellers waited out the bombings, the tattered acting troupes who tried to keep everybody's spirits up, the codebreakers at Bletchley Park, the ambulance drivers, the kids orphaned by war, and all the innocents whose lives have been destroyed by it. Through the eyes of our historians Mike, Mary, and Polly, we see firsthand why staying on the homefront required just as much bravery - if not more - than going to war.

There is a lot of jumping around in time, but the book still unfolds slowly enough that you can appreciate all the research Willis has done to build such a realistic world. As Polly and Mary start to reconcile themselves to the idea that they may be stuck in London for the duration of the war, they begin to settle down. They take rooms and adopt two orphaned children, Binnie and Alf, whose antics provided comic relief in Blackout. And they work with Mike to find other historians who are visiting the war so that they can follow them back home through the "drops" they use to zoom through the timestream. They're joined by their teacher Mr. Dunworthy, who has tried to retrieve them and found himself stuck too. And Dunworthy's nephew Colin, who has yearned for Polly's affections since he was a teenager and she many years his senior, spends his twenties trying to figure out how to rescue them. (Which conveniently brings them into the same age range.)

One of the central mysteries of the novel is why their drops have stopped working. The answer, which gradually surfaces, has to do with the nature of time travel itself - and the unexpected role that historians are playing in what we think of as established historical fact. Though this novel is richly emotional and full of historical detail, it stumbles when Willis has to account for the behavior of the timestream. Though she makes a weak gesture at describing it in scientific terms as a "chaotic system," it becomes obvious that the timestream is, in fact, a stand-in for God. One of the central questions that characters ask is whether "good actions" are pleasing to the timestream, and if they're trying to be good people if the timestream will be kind to them.

Making the timestream into a religious metaphor undermines a lot of the good work Willis has done elsewhere in the novel, establishing the realistic setting and giving us characters who are all scientists at heart. Especially when the entire structure of the story rests on solving the mystery of why time travel is no longer functioning, it's a bit of a letdown to discover that in this novel the answer seems to be "benevolent mystical hokum." If Willis had only written a historical novel, she could have allowed her protagonists to actually wrestle with the meaning of God and religion in a dark time, the way people in World War II would have. Instead, we get a mixture of disappointingly bad science and unrealized philosophical musings.

That said, both Blackout and All Clear make for a compelling, rich historical story whose characters are drawn in loving detail. And Willis' attention to detail is more than enough to make up for problems with plotting.

All Clear is available now, at your favorite indie bookstore!