A team of physics-obsessed students from Leeds take on three Spanish-born brothers, in a bid to build a machine that allows Richard Hammond to water the plants without getting up from watching the TV. With surprise challenges involving buoyancy and garden shears thrown in, the teams need to think extra hard to devise a winning machine - with some spectacular, and occasionally disastrous, results.

Two winners from the heats go head-to-head for a place in the final. The challenge this time is to create an ingenious chain reaction machine that allows Richard to cook sausages in the kitchen, without leaving his desk in the study. Zach Umperovitch is the expert judge and Shini Somara fills in the science behind the teams' eccentric contraptions.