While Zack along with his classmates, visited the museum for a school trip, Zack touched a field phone which gave him shell shock, just like a soldier who had also used a phone in World War I. Now, whenever Zack is exposed to an old object, his personality transforms into the owner of the object. Spencer and Cam must find a way to reverse the effect before Zack touches an object that did not have an owner or existed before the Holocene Period, where humans were not alive yet. (thetvdb.com)