In today's episode Maddie is finding out about different gates that open and close. She visits a canal lock to find out how canal boats travel up and down hill. Maddie jumps aboard with her special steady camera as the canal boat moves through a lock so we can see the gates in action. Next, Maddie visits a blacksmith's workshop to find out how a decorative steel gate is made. We see the pieces of steel being cut and welded together. Maddie uses a special thermal imagining camera to see the sparks fly, and how hot the metal becomes, when it is joined together.