Interstellar Pig by William Sleater

Interstellar pig by William Sleator
I am a little strange about scaryness, as you may have noticed in my last post. Let me explain. Once I was reading some books that I can't remember the title of, and there were injuries, games where people hunted other human beings [hunted: searched for and killed on a private island], and other pretty gory stuff. But it was science fiction. I didn't mind. Until the very last [or was it next to last?] chapter where they locked a bad guy [really girl; I didn't think it would otherwise sound right] in a thing like a cubicle with a roof and were gassing her. When they told her over the vid cam, she held pearls in front of the camera. The lady on the other end was very upset, as the gas ruined pearls. Now that is a frightening thought. I can't tell you how my mind works, but this gives you an idea.
Anyway, back to the book.
there is a boy who is a loner, gets sunburned very easily, and is very suspicious of all activities. He is staying in a beach house with his parents over the summer[Do they at all care about him?]. He meets the people in the cement structure 10 yards away who were very, very upset that they couldn't stay in the house his family was staying in, which is understandable because theirs is very small for three people to stay in and is a horrid shade of pink.
But it is still suspicious when they keep asking to go to his house, and even more so when they pick up every yearbook, pot, and article of clothing in the summer house. And the finger the scrapings on the wall in his room. It gets creepy and cruel from then on, but my favorite part is the last few paragraphs.
Mom's rating:click here [poor]
My Rating: *** C [passing grade, but just barely]
Age Level: 11-15 [best guess]
PS. The reason I talked to you about my weirdo psychology is that I was almost scared to death when they said what 'the piggy' looked like. If you read this book you will probably think this strange.