THE IDEA OF A SINGLE moment on which the fate of a whole world depends is popular, and not just with the authors of alternative histories. For many Brazilians, such a moment, perennially discussed and revisited, happened on July 16, 1950, when Brazil lost the World Cup.

Marcelina Hoffman knows she’s on to a winner with her idea for a reality TV show: she will track down the goal-keeper who missed the ball 56 years earlier and put him on trial before the public.

The only problem is that someone who appears to be her exact double is determined to stop her.

Ian McDonald’s Brasyl alternates Marcelina’s adventures in present-day Rio de Janeiro with two other stories set in different periods.

In 1732, the Jesuit Father Quinn journeys into a Portuguese colonial heart of darkness as he searches for the truth behind a legend of murderous, avenging angels; while, in 2032, deep in the surveillance society that São Paulo has become, the street finds its own uses for a deadly new technology.

Gradually, the separate stories are braided together into a brilliant, kaleidoscopic novel that’s both a portrait of a country and an exploration of the wilder shores of theoretical physics.

Brasyl is McDonald’s best book yet, written in a vivid, almost hallucinatory style that’s perfectly suited to his fascinating subject.

In Peter F. Hamilton’s The Dreaming Void, humanity has managed to surmount all the problems that we face today, conquering death, settling new planets and coexisting with alien races. But no one really understands the Void: a barrier created billions of years ago that will eventually expand to consume the galaxy.

A new religious movement, Living Dream, intends to penetrate the Void, to reach the universe beyond; the Raiel, an alien race of Void-watchers, warns that any such attempt will trigger a catastrophic expansion and mass destruction. But when did threats ever stop true believers?

This is thrilling stuff; compulsively readable and abundantly full of ideas. The only drawback is that, as it’s the first volume of a new trilogy, we’ll have to wait to find out whether our galaxy will be destroyed. Cliff-hangers are tense enough, but this is a planet-hanger.

“She’d read a lot of books like this, where the girl wakes up and she’s a beautiful princess in another world. But she always goes back again.” But when it happens to Miranda Popescu in Paul Park’s A Princess of Roumania, she realises she is home. What had seemed to be her ordinary life in small-town Massachusetts was an elaborate fantasy conjured up to keep her safe as she was growing up.

Now she must confront her fate in a world where blond savages roam the American wilderness and magic plays a part in European politics.

Fans of more simplistic fantasies may be puzzled by the psychological complexities of this superior alternate-history tale, but admirers of the subtler ambiguities of John Crowley or Philip Pullman will find it rich and rewarding.

Brasyl by Ian McDonald

Gollancz, £18.99; 512pp

Buy the book here at the offer price of £17.09 (free p&p)

The Dreaming Void by Peter F. Hamilton

Tor, £18.99;

Buy the book here at the offer price of £17.09 (free p&p)

A Princess of Roumania by Paul Park

Tor, £6.99; 320pp

Buy the book here at the offer price of £6.64 (free p&p)

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