Boys Rock By Phyllis Naylor

(Boy/girl # 11)
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Mary Lou Finney is less than excited about her assignment to keep a journal over the summer. Boring! Then cousin Carl Ray comes to stay with her family, and what starts out as the dull dog days of summer quickly turns into the wildest roller coaster ride of all time. A wonderful story of contemporary teen life.Wally Hatford dreams of long lazy days far away from school and Caroline Malloy. But Wally, the best speller among the Hatford brothers, gets roped into helping them with a summer newspaper project that will earn the twins school credit.
What does that get Wally? When he hears scratching noises coming from Oldakers’ bookstore cellar, Mr. Oldaker trusts him to keep a secret that could turn into a scoop for their newspaper. Wally worries that the secret may be too scary to keep to himself. 
What’s worse, the Malloy girls have horned in on the newspaper. If there’s one person Wally won’t spill his secret to, it’s nutty Caroline Malloy. No matter what it is!