The movie centers on when Arthur neglects Pal for one day and during that day, Pal manages to get out of the house and sets off on an adventure eating whatever comes his way, and exploring the town of Elwood City. However, once Arthur notices Pal's gone missing, it's up to him and his friends (Buster, Brain, Franchine, Binky, & Prunella) to search the town and find him. With many moments where Arthur & Pal's paths cross (but they end up missing out on each other), it takes Buster, Arthur and DW to connect clues and follow the path Pal's traveled.