Hybrids — Robert J. Sawyer

In Hominids, Robert J. Sawyer introduced a character readers will never forget: Ponter Boddit, a Neanderthal physicist from a parallel Earth who was whisked from his reality into ours by a quantum-computing experiment gone awry -- making him the ultimate stranger in a strange land.

In that book and in its sequel, Humans, Sawyer showed us the Neanderthal version of Earth in loving detail -- a tour de force of world-building; a masterpiece of alternate history.

Now, in Hybrids, Ponter Boddit and his Homo sapiens lover, geneticist Mary Vaughan, are torn between two worlds, struggling to find a way to make their star-crossed relationship work. Aided by banned Neanderthal technology, they plan to conceive the first hybrid child, a symbol of hope for the joining of their two versions of reality.

Meanwhile, as Mary's Earth is dealing with a collapse of its planetary magnetic field, her boss, the enigmatic Jock Krieger, has turned envious eyes on the unspoiled Eden that is the Neanderthal world ...

Filled to bursting with his signature speculations about alternative ways of being human, exploding our preconceptions of morality and gender, of faith and love, Sawyer's Neanderthal Parallax trilogy is a classic in the making, and here he brings it to a stunning, thought-provoking conclusion.