Every short story in this wonderfully varied collection has one thing in common: each features some alteration in history, some divergence from historical reality, which results in a world very different from the one we know today. As well as original stories specially commissioned from bestselling writers such as James Morrow, Stephen Baxter and Ken MacLeod, there are genre classics such as Kim Stanley Robinson's story of how World War II atomic bomber the Enola Gay, having crashed on a training flight, is replaced by the Lucky Strike with profoundly different consequences.

In an age of exploration, the crew of the freetrader Pelquin's Comet set out to claim a cache of alien technology that will make them rich, but they are not the only interested party and find themselves in competition with a major corporation. They are also lumbered with an unwelcome passenger - an agent of the bank funding their expedition - who may be a great deal more than he seems. High octane adventure, dark secrets, hidden agendas and double-cross lie in store for the Comet and her motley crew as they pursue their goal to very edge of human space.