In A Pickle — Beth Overmyer

As if angry nuns and bullies weren't enough to handle, a time-traveling orphan gets caught up in a murder. Charlie Pickle can't stay put in the year 1920, due to an annoying habit of time-traveling. On a trip back to 1910, he meets a man with a secret. Murder makes the headlines that day, and Charlie's new friend knows who the guilty party is. Now, not only does Charlie have bullies and murderers to contend with, he's got some history to fix.