Engineering enthusiasts from around the UK competing to create the best chain-reaction machines from everyday objects. In this episode, three brothers from Somerset and a team from Loughborough University are challenged to build ingenious devices that will allow Richard to straighten his duvet and `make the bed" without leaving the bath tub. Machine guru Zach Umperovitch is the expert judge and Shini Somara fills in the science behind the teams' eccentric contraptions.