Triploidy

A medical mystery ... and a threat from beyond the stars.

For Jon and Marianna Knox, the birth of their daughter Persephone marks the happiest day of their lives. 

Until they learn that Persey is suffering from a rare but fatal condition called "triploidy."

Her doctors are baffled, and with good reason-because the source of the little girl's genetic malfunction is not of this Earth. It lies out beyond the orbit of Saturn.

And it's coming for all of us.