Just to let you know exactly where all this is kind of headed towards, the novel's premise is often somewhat accurately summed up as being 'a love triangle with two bodies' 'somewhat', because by the end of the book it's actually more like a love quadrangle with three bodies. which gets more than a little awkward when she actually does succeed in finding them, only to be kept as a prisoner since, duh, she's one of Them now.

This combination leads her to risk absolutely everything to find Jared and Jamie. Eventually she even grows to consider Melanie herself a friend, despite originally wanting her to disappear. This means trouble for Wanderer of course, since not only are human senses and emotions more intense than any other body she's ever experienced, so too are human memories more ridiculously vivid - and Wanderer finds herself inevitably growing to love Melanie's man Jared and brother Jamie, even though she's never met either. However, it turns out that knowing your body's going to be taken over by a Soul allows one to fight back, and Melanie fiercely resists giving up intel or her mind in an effort to protect both the man she loves and her younger brother from sharing the same fate. and enter Melanie Stryder, one of the few remaining wild humans, who's just been captured sneaking around Chicago and is now Wanderer's host.

Enter 'Wanderer', a 'Soul' (alien brain parasite) who's been unusually restless, going from one world to the next. aside, of course, from that pesky handful of 'wild' humans, who caught on sooner and have still managed to avoid capture. It takes place After the End, where a successful infiltration-style Alien Invasion means the Puppeteer Parasites have made the world a more pleasant and peaceful place where they can just sit back and enjoy life. The Host is a 2008 Science Fiction novel by Twilight creator Stephenie Meyer, and was both her first sci-fi work and her first adult novel.

The Seeker by Stephenie Meyer