"Do Not Enter", the little board said. To my mind, that's like hanging a big flashing neon sign up saying, "Come in darling". So in I went. I wish I hadn't. They were waiting for me: twelve monsters in a semi-circle, silent and staring. It was a neat trap, and the indications were that the end result was going to be equally well executed. Executed, oops, shouldn't have thought that word. It sent a ripple of anticipation down my captors' horny plates.
Perhaps I should start at the beginning, and, seeing as I may not be around for much longer, I'll tell all.

I am an adventurer, travelling through time and hopefully one day, space. So far, I had achieved time travel back and forward along the regular dimensions, and can travel up to 3.142857142857 light years in distance through space, in my creation, Zonga Loid. As l am from Earth, 3.142 etc. doesn't help too much as there isn't another star system within that region. Because of this I confine my trips to time travel, hoping to find the vital clue which would open the door to that vacation of a lifetime, the Gigantomachy Inn in the Alpha Centauri system.
The first and last time I tried space travel I took my travelling companion, a semi-intelligent primate called Urang. We set off really early one morning at sparrow-fart. Such was the speed of Loid, that I had hardly peeled my banana and Urang had only taken one bite of his lunch, when Zonga came to a complete and immediate stop.

"Sorry travellers", it said, "Meet Pi". Urang, fluent in seventeen animal languages, including human, took to saying this every time he had a bite of a rat sandwich, and I guess the meaning hasn't changed much over the millenniums.
Anyway, that's how I first came across the Pi barrier. Some sort of field for preventing humans from exploring space, or perhaps escaping into the galaxy, until we are clever or calm enough perhaps. So far, I've been unable to conquer its deepest secret, although I have made some early discoveries. It is a constant (distance from the earth). Well, that's it really, so I decided to start of an investigation that would take weeks and eras, and I began by looking up the complicated origin of Pi.

First port of call was Archimedes. For a while he thought I was his long-lost father, and I taught him everything he knew, especially about baths and water. I also slipped him a few special dormant codes which only l would recognise, thus helping me get through high school maths centuries later, in my earlier years. Clever hey?
I enlisted the help of prominent mathematicians throughout the ages - Euclid, Chongzhi, Ramanujan, and more. I even got Newton to have a dabble. It was during a heated debate with Sir Isaac that a new idea sprang to mind. (Since that day I've never eaten that most sacred of fruits, the worm-ridden apple. Can you believe a mushy one actually fell on my head). In a flash of inspiration, it came to me that Pi's true worth was in the fifth dimension, and I saw the answer clearly. After that quick flash I thought "Urgh", and assuming that Isaac had thrown it at me, I lobbed one back.
He then said, "Oh, now I see what you mean about grave situations".
"No, no!", I replied in frustration. "Gravity". After re-explaining it to him for a further couple of hours, most of my own personal flashing had stopped, and I was only left with the vaguest notion of what had occurred. (I've since adopted that vague look as a disguise. In fact, I'm using it right now, as I face down the monsters).
This led me to take a short break, and I got caught up in King Arthur's quest for the Holy Grail. After having a killer of a bite from a white rabbit, I had some doctor look at it. A useless quack who offered me a plate of fish fingers and custard. So I gave him a jelly baby as payment, ha-ha. I guess that's why you always hear of Merlin, and not this doctor bloke.

Still, back to reality, and knowing that l was firmly on the trail, I set out to search for my own particular 'grail', the Pi from the apple idea. I soon had Zonga zooming back and forth among the centuries, tapping the greatest creative minds. You know how it is, a decimal point here, a reverse osmosis equation there, it all adds up. Some of the best initial ideas came with Einstein's work on relativity, from which we developed E=mc2.
Albert was convinced E=mcc would be more correct, but I said the cricket club wouldn't like that and we should try the other one first. He took a bit of convincing, but finally agreed the relativity formula would be written as E=mc2. It didn't help too much at that time though - I felt there was still an ingredient missing from the pot.
I then went forward in time, to late in the 27th century. There I helped humanoit E7298/CS put the final touches to the famous-to-be First Law of Time. This was developed from an unsuspected source - the undented shell of an ostrich egg. It turned out to be a perfect application for Pi in the fourth dimension and came agonizingly close to the breakthrough into the fifth. I modified Loids modulator accordingly, and thought maybe an older, bigger, smoother, and more dynamic egg?

So we travelled back to the land of the dinosaurs, to look for 'the great egg'. (Note here that ostriches first appeared a million or so years after the extinction of the dinosaurs, but I was hoping for a connection - shell texture or something similar). These great reptiles had completely disappeared off the face of the Earth by seventy million years ago, and I had to make my biggest jump ever. A hundred and fifty million years into the steamy swamps of pre-civilised Earth history. Even Zonga was nervous, leaking oil everywhere, and we were very pleased we had recently added the quantum push-pull effect to Loid. I was after a diplodocus, the largest of the sauropods and fortunately a vegetarian.

As potluck was what was needed, for a change it was potluck I got. I arrived on the edge of a forest overlooking a strange ceremony. Another sauropod, the smaller and trimmer brontosaurus, was being initiated as leader of an imminent migration. The queen diplodocus was present and had just laid a surprise cluster of six eggs. Her private bodyguard of a dozen stegosauruses, (the same guys with whom who I am presently engaging with sugary sweet smiles and vague, innocent looks), were fiercely nudging these into a defensive circle. Zonga's extensive library informed me that they would be unlikely to move the eggs before they had been water-blessed after 24 hours. I would therefore attempt to borrow an egg under cover of darkness.

Events moved quickly, and I still haven't had time to organise my thoughts into a logical sequence. It seems fairly obvious that the egg is the key clue I was looking for. I'd had it for 23¼ of the 32½ minutes Zonga needed for complete analysis, when they came looking for me. Stalling them wasn't too difficult, I used a recorded bellow from a tyrannosaurus rex. This scared the, well, whatever twenty foot long horny-plated leaf-eating bodyguards have, out of them for the remaining ten minutes. I placed the egg outside Loid before making a quick exit, but unfortunately left my fingerprints on the shell. Proof that the answer I needed was now somewhere in Zonga's circuitry is shown by the fact that I ended up standing in a room of a trailer camp, aptly named Star-Lite Star-Bryte, in the 21st century with twelve drooling stegosauruses. So, they too can time travel. It is no comfort to me that they don't eat meat, as they hate all forms of carnivores. Their armour plating and heavy tails were well known for beating off gangs of marauding meat-eaters in their own era.

Acting nonchalant and unconcerned - putting on a brave face as it were, (well, makes a change from the ugly one I usually carry around), I took out my three-day old jam butty and started to eat it. This had an extraordinary effect, as the stegosaurus's started to grunt excitedly to each other. One of them came up to me. As I took evasive action and dropped the half-eaten jam sandwich, an engraved metallic plate fell at my feet. I picked it up a read in perfect English, except for the lisp:

......
"You are reading one of two pothible outcometh. The other one wath your death warrant. You have therefore thomehow convinthed my bodyguard that you are worthy of life. However, you have dethecrated one of my unhatched before it wath bathed with thmelly thwamp water, and therefore become itth guardian. You were traythed from the thent of your hand, and will return with the thtegothorutheth. We are preparing for our migration back to the future in the Vega thithtem, and you will accompany uth. The young oneth true father, a half-blind low-flying pterodactyl, could not be found. You apparently know thome of the wayth of time and thpayth travel and will learn much more with uth. Our mithion ith complete, and our way of life here ith almotht finithed due to oxygen richation. We predict in the near future all the forethtry will die off from lack of carbon dioxide and will think into the thwampth.
Love and kithith, Gloria, Queen".
......

Well, you could have knocked me down with a feather. I'm glad I didn't have the ham sandwich out of the other pocket though.
I had to play for time. "Do you know Baby Sinclair"? I asked in a flash of inspiration.
I think they did as they all said in unison, "Not the Mama".
Anyway, that gave me the few seconds necessary to dash through the door and yell for the Loid. As Zonga caught me, she was already accelerating in three and a half dimensions; and I just about held myself together, but it was touch and go. Next time I tell a story, I'm going to use a stunt double for the dangerous bits.

As soon as we had left a complicated false trail, which included flying through the Earth only just before it solidified and got a speck of cosmic dust in my eye, Zonga told me the history of the egg-shell.
"I have some good news for you, when you've pulled yourself together". So it did show. "That egg was a real breakthrough, even though some of the data was a little scrambled after you dropped it. I also read some embedded passed-on brainwaves in the embryo which makes an interesting tale. You really did hit your potluck with these two species. A diplodocus did not originate on this world. They came from Vega to save the Earth's great reptiles from a cosmic fate. They stand for: Dinosaur lnter-Planetary Liaison Organisation Directing Official Contact, Under Supervision".
"The supervision came from a creature known as Christo", continued Zonga. "Christo was a being genetically created for this planet's conditions, and was so able to survive anything that came her way. She stayed on after the migrations had finished, wandering the Earth to make sure there were no reclusive pods roaming in ignorance, and became a heroic legend in the minds of our reptilian predecessors".
"Unfortunately, she stayed too long, and herself and her eggs became damaged by the Great Catastrophe. When Christo did in fact try to leave, she was also repelled by the Pi-barrier due to her genetic damage and was doomed to spend eternity on Earth. So Christo went forth and multiplied, and still exists today somewhere, as an unassuming ostrich, hidden amongst the species she created".

So, even Christo was trapped. This indicated to me that part of her make up had been damaged, a DNA strand or similar. I needed a restful place to sit and think things through, and could think of no better meditation than watching paint dry. Michelangelo's paint to be exact, at the Sistine Chapel.
Wait a minute - Sistine, that rings a bell. No Cysteine, that's it. An amino acid. Part of the body's functioning make up, and symbol 'c'.
"Hey Zonga", I asked. "Tell me about amino acids".
I managed to shut her up about four hours later by physically chucking a spanner into her works, but a few good points stuck. Another amino acid, methionine (symbol 'm') also exists. So, if you have a tripeptide chain of methionine - cysteine - cysteine (mcc), which does not occur naturally in the body, you may have the key to the Pi barrier.
It appears that that old goat Einstein was right after all. The formula is E=mcc. I must travel back and apologise to him, one day in the future.

"Hey Zonga", I asked. "In as few words as possible, can you manufacture a tripeptide chain for that purpose"?
"Easy Peesy. I just have to hit your head hard, 3.142 mm above the dead-centre of the temporal lobe. This spanner should do nicely".
"Ha-ha, I don't think".
"Or you could just drink this".
If you could bottle a machine smile in a voice, that would have been it.
But Zonga hadn't finished. It seems there was another, unexpected aspect to the story, the creation of the Pi barrier itself, and the final confirming clue, which I will summarise.

The Pi-barrier was setup by an ancient civilisation from a neighbouring solar system, and their local agents were known as the mythological beings Venus and Cupid, the Goddess of Love and her son. As you know, they escaped from Typhon in the battle of the giants by transforming into fish and flinging themselves into the sky to become the constellation Pisces. Notice that it's Pisces, and not Piscesquared.
So, it's all come together at last - Pi barriers, relativity and mcc.
If you hit the Pi barrier 3.142 light years away, at exactly the correct relative mass/speed ratio, with the tripeptide key, you can pass through.
Alpha Centauri here we come.

"Also", Zonga added as an afterthought, "Since I've now cracked the secrets of that particular era, I've found that Christo had a special ward. It appears that one dinosaur did not migrate in time but elected to wait for the return of her adopted father. She had to adapt to a life under water to escape detection and is still waiting. Will we be taking Nessie to Alpha Centauri with us"?
Oh well. I hope Urang doesn't mind sharing a room. I wonder if Gigantomachy Inns give hospitality stamps based on size...