Alan Markfield
Diane Kruger stars in "The Host."

OK, let me see if I’ve got this straight. Earth is in better shape than it has been for … well, probably since the beginning of humankind, because aliens have invaded the planet and embedded their little ethereal, sparkly, wispy souls into human bodies?

Then, if I’m getting the drift, these kind, gentle, totally honest and loving creatures take over everything, including the infrastructure, the homes, the vehicles, well, everything until, ah, well … until what? I’m curious because, we are informed, they’ve done this same shtick on other planets, too! And, I guess, these kind and gentle souls think nothing of invading a human body and muscling the human soul or spirit out of the way or into oblivion?

Of course, humans are taking the advice of the poet to “not go gentle into that good night,” and are fighting back, but it’s a losing battle. Some simply commit suicide, some have hidden themselves out in the desert and some will simply not be completely pushed aside within their own skin.

Enter Saoirse Ronan as Melanie, who has been on the run with her little brother, Jamie. Finally, she’s cornered by the aliens and jumps from a window to save her brother. She is captured, clings to life and has the soul of “Wanderer” implanted within her. It’s the promise to her brother to return to him that keeps her alive and keeps her will strong even while hosting the alien being.

Her struggle to maintain some control over her being and desire to return to her little brother creates challenges for Wanderer and the aliens who are trying to use what remains of Melanie to find other hidden humans.

All right, my head is about to explode. Suffice it to say that Melanie and Wanderer, cohabitating the same body, get to know each other, believe it or not, fall in love with two different humans, end up helping the resistance and — stop me, I can’t go on.

During the first part of the film, I just about went off the edge, then it drew me back in with a few intriguing sci-fi elements, but then, off the edge again. It was interesting to see the rebel stronghold, but I can’t help but wonder what William Hurt, as Melanie’s uncle and leader of the rebellion, must have been thinking as he, too, witnessed some of the silliness, implausibility and outright laughable stuff going on around him.

I’m not the right demographic and I’m not the right gender, but hey, for all I know, I could be the host for an alien being and maybe that’s why I don’t get this film. Come to think of it, that could explain a lot. Just 2 pity stars for “The Host,” which is rated PG-13.