Chuggington: Can't Catch Koko

When Harrison breaks down, Koko volunteers to replace him on the night shift, determined to make the fastest run ever. But Vee insists that Wilson and Brewster go too, despite Koko's protests that Brewster will slow them down. Koko races off, teasing Brewster about being a 'slowcoach.' Suddenly she shudders and slows to a stop and Brewster and Wilson overtake.