Cryptonomicon

Waterhouse must either move forward or be pulled onto his back by Duffel and left squirming helplessly in the parking lot like a flipped beetle, so he staggers forward, across the street and onto the wide footpath into the woods. The Bletchley girls surround him. They have celebrated the end of their shift by applying lipstick. Wartime lipstick is necessarily cobbled together from whatever tailings and gristle were left over once all of the good stuff was used to coat propeller shafts. A florid and cloying scent is needed to conceal its unspeakable mineral and animal origins.

It is the smell of War.

Waterhouse has not even been given the full tour of BP yet, but he knows the gist of it. He knows that these demure girls, obediently shuffling reams of gibberish through their machines, shift after shift, day after day, have killed more men than Napoleon.

He makes slow and apologetic progress against the tide of the departing day shift. At one point he simply gives up, steps aside, body-slams Duffel into the ivy, lights up a cigarette, and waits for a burst of a hundred or so girls to go by him. Something pokes at his ankle: a wild raspberry cane, furious with thorns. It supports an uncannily small and tidy spider-web whose geodesic strands gleam in a beam of low afternoon light. The spider in the center is an imperturbable British sort, perfectly unruffled by Waterhouse's clumsy Yank antics.

Waterhouse reaches out and catches a yellow-brown elm leaf that happens to fall through the air before him. He hunkers down, plants his cigarette in his mouth, and, using both hands for steadiness, draws the sawtooth rim of the elm leaf across one of the web's radial strands, which, he knows, will not have any sticky stuff on it. Like a fiddle bow on a string, the leaf sets up a fairly regular vibration in the web. The spider spins to face it, rotating instantly, like a character in a badly spliced movie. Waterhouse is so startled by the speed of the move that he starts back just a bit, then he draws the leaf across the web again. The spider tenses, feeling the vibrations.

Eventually it returns to its original position and carries on as before, ignoring Waterhouse completely.

Spiders can tell from the vibrations what sort of insect they have caught, and home in on it. There is a reason why the webs are radial, and the spider plants itself at the convergence of the radii. The strands are an extension of its nervous system. Information propagates down the gossamer and into the spider, where it is processed by some kind of internal Turing machine. Waterhouse has tried many different tricks, but he has never been able to spoof a spider. Not a good omen!

The rush hour seems to have ended during Waterhouse's science experiment. He engages Duffel once more. The struggle takes them another hundred yards down the path, which finally empties out into a road just at the point where it is barred by an iron gate slung between stupid obelisks of red brick. The guards are, again, RAF men with Sten guns, and right now they are examining the papers of a man in a canvas greatcoat and goggles, who has just ridden up on an Army green motorcycle with panniers slung over the rear wheel. The panniers are not especially full, but they have been carefully secured; they contain the ammunition that the girls feed into the chattering teeth of their ravenous weapons.

The motorcyclist is waved through, and makes an immediate left turn down a narrow lane. Attention falls upon Lawrence Pritchard Waterhouse, who after a suitable exchange of salutes, presents his credentials.

He has to choose among his several sets, which he doesn't manage to hide from the guards. But the guards do not seem alarmed or even curious about this, which sets them distinctly apart from most whom Waterhouse has dealt with. Naturally, these men are not on the Ultra Mega list, and so it would be a grave breach of security to tell them that he was here on Ultra Mega business. They appear to have greeted many other men who can't state their real business, however, and don't bat an eyelash when Lawrence pretends to be one of the naval intelligence liaisons in Hut 4 or Hut 8.

Hut 8 is where they decrypt naval Enigma transmissions. Hut 4 accepts the decrypts from Hut 8 and analyzes them. If Waterhouse pretends to be a Hut 4 man the disguise will not last for long, because those fellows have to actually know something about the Navy. He perfectly fits the profile of a Hut 8 man, who need not know anything except pure math.