Hardcover.

Its almost time for school to start again, and Nikki is a little worriedbut, as always, she has her BFFS to help. Only, it turns out her friends need Nikkishelp. Nikki quickly gets overwhelmed and even starts feeling sickwhich is when her little sister, Brianna, takes her chance to steal Nikkis diary! How much damage can Brianna do before Nikki is back on her feet?