Been a long time since I read it, but it's set after the Alien sometime invasion of Earth and revolves around a trophy wife called Caryn Delacroix, who is haunted by dreams of a Predator and Ailens and someone or something called Ash Parnall.
She ends up joining up with the Predator (a female) and there's all sorts of stuff about buried identities and memories, and then they join up with a couple of soldiers and subsequently end up looking like rejects from a Boris Vallejo painting. I'd have to read it again to see if it makes anymore sense - but it didn't make much sense the previous times I've read it.
As the above would indicate.