The Sleek Geeks have a life-affirming message for you tonight. I am - you are - we are - superhuman. Tucked away in our bodies are the most amazing powers and abilities and the Geeks are ready to explore

Do you know anyone with Bum Breath? Is it you? The Geeks look at the mouth, the bacteria, the gases and show you how to self-test for bad breath. Karl and Adam have tubes stuck down their mouths and noses in the name of science, and Karl sets Adam with the cruellest taste-test ever on prime-time TV. Its all topped off with an original song to Bad Breath from JJJ favs Art v Science

The End is Nigh – well possibly, but it certainly won't be anything to do with the Mayan Calendar. In this episode Karl and Adam sort the molten lava from the palaver and tell you why you should have superannuation plans for 2013 and beyond. As well as dispelling the 2012 myth, the Geeks look at the real threats the world faces. Supervolcanoes, Death Stars, Near Earth Objects, Plague and Nuclear annihilation. But its not all doom and gloom: Adam explains why its best to destroy zombies; Karl critiques the film 2012; Ruben shows you how to makes nuclear style mushroom clouds using a smoke machine and a garbage bin; Richard Morecroft and Tracey Spicer drop in and Rhys Muldoon and Benita Collings leave you with a reading from Revelations that will make you re-assess children's television.

Why do we eat and what does it do to us? This week Karl and Adam examine the science of eating and energy. Karl explains how eating determines our body temperature, and he illustrates the theory by showing a marathon runner collapsing just before the finish line (hyperthermia) and his daughter diving into sub-zero Antarctic waters (hypothermia). Adam takes a group of volunteers on a power walk to show just how much work they have to do to burn off their guilty pleasure. Did you know there are 17 teaspoons of sugar in a can of carbonated soft drink? Ruben sets light to a gummy bear to show how much sugar there is in the innocent looking sweet. We decode the Basal Metabolic Rate (the formula will be available on the website) and explain the process of digestion. We meet a fidgetter, whose constant moving and twitching helps him maintain a healthy weight. Karl debunks the belief that you can lose weight by eating celery. An audience member tries to work out which task takes the most energy in the Rank-o-meter (vigorous arts and crafts, surfing, butchering animals, tai chi) which leads to a discussion on the MET rate – which is the rate at which you burn off energy. We reveal Elvis’s diet and the king makes a rare appearance to perform an even rarer original song ‘Burning Hunk of Lard’.

Back by special demand, Karl and Adam take on yet another episode of answering questions from the studio audience and the website. In this edition Karl and Adam tackle questions about what’s in water other than water? How do you win Lotto (or why you can’t win Lotto)? Why the sky is blue? And what happens to your body when you go under general anaesthetic? Karl conducts a test to see if black cars get hotter than white ones when left in the sun. Karl and Adam try to work out just how strong eggs are by getting Adam to stand on them. You’ll be amazed how much weight they take. Ruben demonstrates what happens when something very hot hits something very cold, by pouring boiling water into liquid nitrogen. A question sent to our website asks “If our body renews every seven years why don’t we look like second-graders?” Karl explains that a new discovery, which is an unexpected side effect of a spike in Carbon 14 from nuclear explosions, has shown that different parts of our body renew quicker than others. Karl explains why the uterus is his favourite body part.

Karl and Adam take us through the fascinating world of colour, and Claudia Karvan joins students of Brent Street School to learn about rainbows.

So what actually happens after you drink a glass of water? How does it come out the other end? We follow liquid through peristalsis all the way to the bladder. We see a remarkable X-Ray of a bladder emptying and amazing footage of the urinary tract. Adam visits a work site to show a Urine Colour Chart - the chart is used so you can tell if you're dehydrated by the colour of your wee. We demythologise the must-drink-eight-glasses-of-water-a-day belief and discuss the existence of embedded water in food we eat. We also explore the myths that you should wee on a jellyfish sting and that there is a burgeoning market for stolen kidneys. We discuss breaking the seal and stopping midstream, exploding kidneys and how much elephants can wee. Karl claims men have to splatter, and that the same reason men splatter is the same basis for the technology that creates ink jet printing. Ruben uses drain cleaner to make flammable bubbles, it's just up to Adam to set them alight before they blow away. Adam explains why some people's wee smells of asparagus while others doesn't. A group of Australia's premier performers, including Deni Hines, Iva Davies and The Chaser's Andrew Hansen and Chris Taylor collaborate to produce a moving tribute to micturation 'Wee Across the World'.