Jem makes his own diamond, and then proves that they aren't forever. Yan explains the science of popcorn, while Dallas investigates why we haven't cured cancer yet, and meets the team that hopes to change that.
Liz hits the beach with the Royal National Lifeboat Institution to experience the power of rip currents, Yan attempts to demonstrate evolution by drawing a couple of lines, and Jem is back in the workshop, turning everyday scrap into gold.
Jem witnesses the awesome power of rockets with the Bloodhound land speed record project, Yan re-enacts an Ancient Greek experiment to measure the earth's circumference with a couple of sticks, and Dallas goes in search of a robot to call his own.
Liz investigates new stem-cell research that could change the face of organ transplant surgery, Yan tries out the Nocebo effect (the placebo effect's evil twin), and at a memory boot camp Dallas discovers how to remember where he left his keys.
Dallas stops brushing to discover what causes tooth decay and gum disease, Yan explains why refreezing food is not a great idea, and Jem investigates new research suggesting that electric lights can play havoc with the way we sleep.