Ash has spent years thinking he's an ordinary husband and stepfather, until he learns he's actually an alien with his memories wiped clean, and that an invasion he can't remember agreeing to fight is closing in on Earth. To keep his own kind from a device called the Puncture, he pieces together a past he no longer remembers living, with only his resentful stepdaughter Darcy willing to help—and an alien impersonating an FBI agent hunting them both. It's an Invasion-universe novel told from the invader's side.
Summary by Loreful, from public sources