Postman Pat and the Double Disguise Postman Pat : Season 5 Episode 16

Greendale is holding a charity sale and Julia is sorting through everyone's donated items. Tom and Katy try to help out, but only end up making a big mess, so Julia shoos them off to play. As Tom and Katy wander around the village, they come upon a variety of people who need help - Ted, Ajay, Pat - but all of them say the jobs are for grown-ups. Then, a part for Ajay's train goes missing and the only ones who can help are the twins... and they find that sometimes, being small isn't bad after all.