If you're one of the first three people to solve the final puzzle, you're in with a chance of meeting Marcus and winning this beautiful 3D-printed sculpture.

The Code might have come to an end but the Code Challenge is just hotting up. With the transmission of the third and final episode of the series you should now have all the clues in place to move on to the next stage of the competition. And the first three to crack this will get the chance to meet me and battle it out in a final round on the 10 September.

One of the most exciting things about making this series has been seeing how the Code Challenge has really got people actively involved in the content of the programmes. Mathematics is not a spectator sport and the interactive treasure hunt has provided a fantastic extra dimension to exploring the maths at the heart of our world. I never expected our prime number community challenge to be completed so quickly. Viewers came up with some really inventive ways to find primes: from the countdown clock at the launch of the Atlantis space shuttle which got held at 00:31 to finding people who'd got primes tattooed on their arms (well it was actually me who found that one).

One of the really exciting things about being a mathematician is having one of those "aha" moments where you suddenly make a breakthrough on a problem you've been working on for ages. It really is the buzz that I live for as a mathematician. It's been great to see that viewers have been having their own "aha" moments solving some of the trickier bits of the treasure hunt whether it was cracking the formula behind the puzzling dice in episode 2 or suddenly seeing numbers in the stars in episode 1.

It's always a bit sad to see the last programme go out in a series. When you make a TV show like this it really does become part of your life. We started filming the Code in February when we visited the Merker's mine with its extraordinary cubic salt crystals and we finished in mid-June when we witnessed the total eclipse of the moon in Cyprus. It's one of the real privileges of making TV to have the chance to visit so many fascinating locations during the months of filming. But we have been working on the programme for years before the first shots were taken, trying to find the best way to bring a very abstract subject like mathematics to life in a visual medium like TV. Although I get to be in front of the camera it must be recognised what an amazing team effort it is to make a TV series like The Code and I have had a great team of people to work with. Thank you to you all.

We hope you enjoyed the series and continue to have fun solving the puzzles. Good luck in the final push to get your hands on the treasure - I'll be meeting three of you in a month's time!

In programme three the true power of The Code is unleashed in perhaps the ultimate challenge: predicting the future. If time travel were possible, it would be easy – I could just come back from next year and tell you what happened. Sadly we don’t yet know how to travel through time, and many of the ways people claim to predict the future, such as gazing into crystal balls or casting horoscopes, are complete mumbo-jumbo. If you really want to know what’s going to happen tomorrow, next year, or far into the next millennium, your best bet is mathematics.

To prove my confidence in the power of maths to look into the future I was even prepared to put my life at the mercy of The Code. Ever since we started making the series, there was talk of a death-defying stunt that I would be subjected to. The stunts varied from: driving a car at the right speed round a loop the loop so I didn’t fall off, standing in front of a wrecking ball as it swung towards me, diving off a bridge attached to an untested bungee chord. In the end we went for The Ball of Death. I had to calculate the trajectory of a massive ball as it was shot down a ramp. Using my maths I had to work out where to stand to avoid being crushed by the ball. Ominously the plan was to make this the last day of filming…just in case I got my sums wrong. See how well I did in this, the final episode.

You too will have to master the maths of projectiles if you are going to make it to the end of the Code Challenge. Our online game for this episode, Kingdom of Catapults, requires you to predict the path of flying fruit to knock out an invading army that wants to capture your castle. Use your maths to defeat the enemy and you’ll release another clue on the way to cracking the Code Challenge.

Another game that involves spotting patterns to predict the future is rock, paper, scissors. To see how good the champions are at reading patterns in their opponents we travelled to the Raven Lounge in downtown Philadelphia to film at the famous Rock Paper Scissors League Championship that is held there each week.

Although it didn’t make the cut I was also entered into the competition to put my own pattern searching abilities to the test. Each competitor needs their own individual RPS name to enter the league. Regulars include Paper Tiger, Slanted Scissors and Silly Putty. I decided to try some academic intimidation and plumped for The Professor. I got through several rounds but eventually met my match in the quarter-finals where I got knocked out by Dick Nasty.

Dick Nasty, Marcus's opponent at the Rock, Paper, Scissors Qualifying League in Philadelphia.

It was when he put out his hand to commiserate me on my exit from the competition that I noticed a rather curious tattoo on his arm: a collection of squares of different sizes corresponding to the numbers 1,1,2,3,5,8,13 with a Fibonacci spiral traced through them. If I was going to be knocked out of the competition it was no dishonour to lose to someone who was prepared to mark his body permanently with the wonders of The Code.

I hope you enjoyed the series and best of luck with the rest of the challenge. After this episode you should be able to find all the clues you need to unlock the second stage, and from there you could be in with a chance to get into the final!

Once you’ve watched the programme you’ll be ready to crack the next stage of our Code Challenge which includes the intriguing: Master of Mosaics. This game is all about spotting the symmetries hidden inside a sequence of beautiful tiles that conceal the fabled Fyodorov family vault. Maybe it's because I spend my life researching the fascinating world of symmetry that this is one of my favourite games of the Code Challenge. Get to the end and another crucial clue will be unlocked.

When we started to make The Code the producers asked me where I would like to go to capture the dramatic examples of mathematics at work . Perhaps I should have said the Bahamas or Hawaii but instead I said that I’d always wanted to go to the northern tip of Northern Ireland to see one of the mathematical wonders of the natural world: the Giant’s Causeway.

The Giant's Causeway in Northern Ireland

I’d seen pictures of the thousands of strange hexagonal columns that cover the coast like a beehive but nothing prepares you for witnessing such beautiful geometry up close. Although filming was absolutely freezing and I almost got swept out to sea by a freak wave, the Giant’s Causeway is a dramatic backdrop to the opening of programme two and it conveys the powerful message that the most efficient solutions to nature's problems are often mathematical.

But our trip to the Giant’s Causeway was probably eclipsed by a visit we made towards the end of the programme to Pixar studios to find out how the film-makers are using mathematics to create the virtual worlds of films like Up and Cars. I think most people’s impression is that Pixar is populated by artists meticulously illustrating the movies frame by frame. But surprisingly, a good proportion of the employees are more versed in the mathematics of fractal geometry than paints and brushes. The great discovery of the 20th century is that the mathematics of fractal shapes is the code behind the way many things form: from trees to mountains, from clouds to waterfalls.

 

Most exciting of all was getting a sneak preview of one of Pixar’s new movies. It was so confidential that we weren’t allowed to point our cameras anywhere near the storyboards hanging on the walls and we were all sworn to secrecy. But I can tell you that mathematics will once again be one of the key ingredients in bringing those pictures to life.

I hope you enjoy the second programme and best of luck with this week's puzzles. You're nearly halfway through the hunt, keep going!

I was particularly excited to film this episode as I got the chance to meet two of my mathematical heroes of the animal world for the first time: the magicicada and the nautilus.

The magicicada is an extraordinary species of cicada that uses my favourite numbers in mathematics, the primes, for its evolutionary survival. To find them we travelled to Nashville Tennessee, home usually to the sound of blue grass and honky tonk. But every 13 years the banjos and basses get drowned out by the chorus of an insect that has fascinated me ever since I became a mathematician. It might seem strange for a mathematician to be interested in bugs but these cicadas are rather special. Only found in the eastern states of north America the cicadas exploit mathematics to help them to survive. They appear periodically but only emerge after a prime number of years. In the case of the brood appearing around Nashville: every 13 years.

I've read about their story, seen their pictures, watched videos of them emerging from the ground. But this year was the first time I've been lucky enough to see them for real. Maybe the fact that 2011 is prime number year was a good omen.

As part of the Code Challenge you will also need to master your primes to survive, not in the forest around Nashville, but in the kitchen of Chef Mersenne in our addictive game Prima Pizzeria. Make it to a certain point and you’ll get an important clue to help you crack the Code Challenge. And remember to keep on sending us pictures of prime numbers in the environment. We’re hoping to get all the primes up to 2011. You can also email pictures to code@bbc.co.uk.

After Nashville it was back up to Brooklyn to come face to face with one of the icons of the mathematical world: the nautilus. The shell of the nautilus is such a thing of beauty that it has become the poster boy for the world of mathematics. But it’s only by turning the dimensions of the shell into numbers that we can reveal the secret to how it grows. Although I’ve seen countless images of the shell, my trip to Brooklyn was the first time I’d seen the animal that actually lives inside the shell. A strange ancient octopus that looked like one of the ood from Doctor Who.

The Code mascot - Fibunnacci - capured by Marcus.

Although he didn’t make the cut there is another animal that deserves a mention. We adopted a very friendly rabbit as The Code mascot who kept us company while filming a very cold sequence at the Sunkenkirk stone circle in Cumbria about the number pi hidden inside all circles. We named him appropriately enough Fibunnacci.

Enjoy the first programme and best of luck with the treasure hunt!

Welcome to The Code. This new series for BBC2 will make you see the world in a completely different way. Because underlying everything that surrounds us, from the natural world to the cities we live in, there is a hidden code that explains why things look and behave they way they do. That code is Mathematics.

My name is Marcus du Sautoy and I’m a mathematician. In the three programmes that make up my new series The Code, I want to reveal to you the hidden language of the universe and let you see the world through my eyes. Watch Pixar movies through the lens of a fractal geometer, listen to the story of Jack the Ripper through the ears of a mathematical detective and discover secret numbers built into ancient stone circles and gothic cathedrals.

But what makes this series so unique is that it is more than just a television programme. Running alongside the programmes is an exciting mathematical treasure hunt full of engaging puzzles, addictive online games and clever conundrums that will take you on an exciting mathematical journey of discovery. Called the Code Challenge it is an experience that combines the intrigue of solving a murder mystery with the addictive playfulness of Angry Birds.

For me mathematics is not a spectator sport. The best way to appreciate and get excited by the power of this extraordinary subject is by immersing yourself actively in its world. The Code Challenge is a fantastic way to play and explore the mathematical language of the universe. And not only is it fun to play but there is a unique and valuable prize awaiting the person who finishes the challenge first.

There will be clues hidden inside each programme to help you crack the Code Challenges but you can already start taking part by helping us to capture pictures of the building blocks of mathematics: the prime numbers. These indivisible numbers are my favourite in all of mathematics – not least because the football shirt I play in for my Sunday League team is a prime, 17. But they are also the most important numbers in my subject because all numbers are built by multiplying primes together. Primes are the atoms of arithmetic.

Your first challenge is to work as a team and send us pictures of the first 100 prime numbers from 2,3,5… all the way up to 541. Perhaps you live at a prime number house, go to work on a prime number bus, have a cow in the local field with a prime number branded on its back. Or perhaps you can find a prime hiding in an unexpected location that would surprise us here at Code headquarters. 

Get warmed up with Froghopper - the first of The Code's online games...

There is also the first of several addictive online games available to play. Called Froghopper it will help you warm-up your geometry skills. Can you pack shapes efficiently to help our frog to get to his destination? You never know, playing this game might help you when you next try to pack the car or a suitcase if you’re off on your holidays soon.

So get your puzzle hats on and good luck in cracking the Code Challenge! Get chatting on this blog or see what everyone else is saying on Twitter.