In Screws, inhabitants of Mammoth Island are in the process of building a new observation tower out of stone blocks when one of the Islanders gets trapped at the top. With the help of a visiting gallant knight and his trusty mammoth, they are able to build a ramp around the circular structure and create a giant simple machine known as a screw. Turning the tower into a giant screw allows the Islanders to spin the tower down into the soil, bringing the trapped inhabitant of Mammoth Island close to the ground -- and saving the day!

Teacher's guide available under Additional info tag. Also available in Streaming on Learn360 under the title "A knight's tale".

Based on the Dorling Kindersley book "The Way Things Work" by David Macaulay.