You will be charged for the one person that does not show. I can tell you that from personal experience, because we were. The morning of our Akersus ADR I was ill, so sent the others on ahead, thinking that as long as our party showed that I wouldn't be charged. Wrong! After we arrived home, I went online to pay my credit card and found a $10.00 charge I didn't know, so called. The CM was immediately able to tell me that it was because one of my party did not show up at Akershus on that particular morning. Others have also posted here on the DIS that they were charged when part of their party couldn't make it.