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But enzymes had a further use。 They made possible chemical reactions that otherwise would not occur。 A biochemist could duplicate the reactions by using great heat； or great pressure； or strong acids。 But the human body； or the individual cell； could not tolerate such extremes of environment。 Enzymes； the matchmakers of life； helped chemical reactions to go forward at body temperature and atmospheric pressure。
Enzymes were essential to life on earth。 But if another form of life had learned to do without them； it must have evolved in a wholly different way。
Therefore； they were dealing with an entirely alien organism。
And this in turn meant that analysis and neutralization would take much； much longer。
***
In the room marked MORPHOLOGY； Jeremy Stone removed the small plastic capsule in which the green fleck had been imbedded。 He set the now…hard capsule into a vise； fixing it firmly； and then took a dental drill to it； shaving away the plastic until he exposed bare green material。
This was a delicate process； requiring many minutes of concentrated work。 At the end of that time； he had shaved the plastic in such a way that he had a pyramid of plastic； with the green fleck at the peak of the pyramid。
He unscrewed the vise and lifted the plastic out。 He took it to the microtome； a knife with a revolving blade that cut very thin slices of plastic and imbedded green tissue。 These slices were round； they fell from the plastic block into a dish of water。 The thickness of the slice could be measured by looking the light as it reflected off the slices if the light was faint silver； the slice was too thick。 If； on the other hand； it was a rainbow of colors； then it was the right thickness； just a few molecules in depth。
That was how thick they wanted a slice of tissue to be for the electron microscope。
When Stone had a suitable piece of tissue； he lifted it carefully with forceps and set it onto a small round copper grid。 This in turn was inserted into a metal button。 Finally； the button was set into the electron microscope； and the microscope sealed shut。
The electron microscope used by Wildfire was the BVJ model JJ…42。 It was a high…intensity model with an image resolution attachment。 In principle； the electron microscope was simple enough： it worked exactly like a light microscope； but instead of focusing light rays； it focused an electron beam。 Light is focused by lenses of curved glass。 Electrons are focused by magnetic fields。
In many respects； the EM was not a great deal different from television； and in fact； the image was displayed on a television screen； a coated surface that glowed when electrons struck it。 The great advantage of the electron microscope was that it could magnify objects far more than the light microscope。 The reason for this had to do with quantum mechanics and the waveform theory of radiation。 The best simple explanation had e from the electron microscopist Sidney Polton； also a racing enthusiast。
〃Assume；〃 Polton said； 〃that you have a road； with a sharp corner。 Now assume that you have two automobiles； a sports car and a large truck。 When the truck tries to go around the corner； it slips off the road； but the sports car manages it easily。 Why？ The sports car is lighter； and smaller； and faster； it is better suited to tight； sharp curves。 On large； gentle curves； the automobiles will perform equally well； but on sharp curves； the sports car will do better。
〃In the same way； an electron microscope will 'hold the road' better than a light microscope。 All objects are made of corners； and edges。 The electron wavelength is smaller than the quantum of light。 It cuts the corners closer； follows the road better； and outlines it more precisely。 With a light microscope like a truck you can follow only a large road。 In microscopic terms this means only a large object； with large edges and gentle curves： cells； and nuclei。 But an electron microscope can follow all the minor routes； the byroads； and can outline very small structures within the cell mitochondria； ribosomes； membranes； reticula。〃
In actual practice there were several drawbacks to the electron microscope； which counterbalanced its great powers of magnification。 For one thing； because it used electrons instead of light； the inside of the microscope had to be a vacuum。 This meant it was impossible to examine living creatures。
But the most serious drawback had to do with the sections of specimen。 These were extremely thin； making it difficult to get a good three…dimensional concept of the object under study。
Again； Polton had a simple analogy。 〃Let us say you cut an automobile in half down the middle。 In that case； you could guess the plete； 'whole' structure。 But if you cut a very thin slice from the automobile； and if you cut it on a strange angle； it could be more difficult。 In your slice； you might have only a bit of bumper； and rubber tire； and glass。 From such a slice； it would be hard to guess the shape and function of the full structure。〃
Stone was aware of all the drawbacks as he fitted the metal button into the EM； sealed it shut； and started the vacuum pump。 He knew the drawbacks and he ignored them； because he had no choice。 Limited as it was； the electron microscope was their only available high…power tool。
He turned down the room lights and clicked on the beam。 He adjusted several dials to focus the beam。 In a moment； the image came into focus； green and black on the screen。
It was incredible。
Jeremy Stone found himself staring at a single unit of the organism。 It was a perfect； six…sided hexagon； and it interlocked with other hexagons on each side。 The interior of the hexagon was divided into wedges； each meeting at the precise center of the structure。 The overall appearance was accurate； with a kind of mathematical precision he did not associate with life on earth。
It looked like a crystal。
He smiled： Leavitt would be pleased。 Leavitt liked spectacular； mind…stretching things。 Leavitt had also frequently considered the possibility that life might be based upon crystals of some kind； that it might be ordered in some regular pattern。
He decided to call Leavitt in。
***
＇graphic of EM crystal pattern＇ Caption： （Early sketch by Jeremy Stone of hexagonal Andromeda configuration。 Photo courtesy Project Wildfire。）
As soon as he arrived； Leavitt said； 〃Well； there's our answer。〃
〃Answer to what？〃
〃To how this organism functions。 I've seen the results of spectrometry and amino…acid analysis。〃
〃And？〃
〃The organism is made of hydrogen； carbon； oxygen； and nitrogen。 But it has no amino acids at all。 None。 Which means that it has no proteins as we know them； and no enzymes。 I was wondering how it could survive without protein…based organization。 Now I know。〃
〃The crystalline structure。〃
〃Looks like it；〃 Leavitt said； peering at the screen。 〃In three dimensions； it's probably a hexagonal slab； like a piece of tile。 Eight…sided； with each face a hexagon。 And on the inside； those wedge…shaped partments leading to the center。〃
〃They would serve to separate biochemical functions quite well。〃
〃Yes；〃 Leavitt said。 He frowned。
〃Something the matter？〃
Leavitt was thinking； remembering something he had forgotten。 A dream； about a house and a city。 He thought for a moment and it began to e back to him。 A house and a city。 The way the house worked alone； and the way it worked in a city。
It all came back。
〃You know；〃 he said； 〃it's interesting； the way this one unit interlocks with the others around it。〃
〃You're wondering if we're seeing part of a higher organism？〃
〃Exactly。 Is this unit self…sufficient； like a bacterium； or is it just a block from a larger organ； or a larger organism？ After all； if you saw a single liver cell； could you guess what kind of an organ it came from？ No。 And what good would one brain cell be without the rest of the brain？〃
Stone stared at the screen for a long time。 〃A rather unusual pair of analogies。 Because the liver can regenerate； can grow back； but the brain cannot。〃
Leavitt smiled。 〃The Messenger Theory。〃
〃One wonders；〃 Stone said。
The Messenger Theory had e from John R。 Samuels； a munications engineer。 Speaking before the Fifth Annual Conference on Astronautics and munication； he had reviewed some theories about the way in which an alien culture might choose to contact other cultures。 He argued that the most advanced concepts in munications in earth technology were inadequate； and that advanced cultures would find better methods。
〃Let us say a culture wishes to scan the universe；〃 he said。 〃Let us say they wish to have a sort of 'ing…out party' on a galactic scale to formally announce their existence。 They wish to spew out information； clues to their existence； in every direction。 What is the best way to do this？ Radio？ Hardly radio is too slow； too expensive； and it decays too rapidly。 Strong signals weaken within a few billion miles。 TV is even worse。 Light rays are fantastically