I give it a 2! I was really good for being a Sifi Thriller. I liked the mystery of it all. I however did not like that there were so may questions unanswered.
Like was the alien really the only one? If it mimicks other forms, did it have its own form before? Also how they hosted people. Could they multiply and host more than one person at a time. Lastly, did the lady live or not. She make survived, but did she become infected and not know it yet? Would know if you were infected?
It wasn't completely horrible. It kept me interested. But if it was the the lady's character who was likeable and reliable, I don't think I would have finished watching it. I wanted to see her survive.