He took from his satchel a toy bow and arrow which he had bought in a street market.
He had discovered that the reason for the carnival atmosphere on Saquo-Pilia Hensha was that the local people were celebrating the annual feast of the Assumption of St Antwelm. St Antwelm had been, during his lifetime, a great and popular king who had made a great and popular assumption. What King Antwelm had assumed was that what everybody wanted, all other things being equal, was to be happy and enjoy themselves and have the best possible time together. On his death he had willed his entire per- sonal fortune to financing an annual festival to remind everyone of this, with lots of good food and dancing and very silly games like Hunt the Wocket. His Assumption had been such a brilliantly good one that he was made into a saint for it. Not only that, but all the people who had previously been made saints for doing things like being stoned to death in a thoroughly miserable way or living upside down in barrels of dung were instantly demoted and were now thought to be rather embarrassing.
The familiar H-shaped building of the Hitch Hiker’s Guide offices rose above the outskirts of the city, and Ford Prefect had broken into it in the familiar way. He always entered via the ventilation system rather than the main lobby because the main lobby was patrolled by robots whose job it was to quiz incoming employees about their expense accounts. Ford Prefect’s expense accounts were notoriously complex and difficult affairs and he had found, on the whole, that the lobby robots were ill-equipped to understand the arguments he wished to put forward in relation to them. He preferred, therefore, to make his entrance by another route.
This meant setting off nearly every alarm in the building, but not the one in the accounts department, which was the way that Ford preferred it.
He hunkered down behind the storage cabinet, he licked the rubber suction cup of the toy arrow, and then fitted it to the string of the bow.
Within about thirty seconds a security robot the size of a small melon came flying down the corridor at about waist height, scanning left and right for anything unusual as it did so.
With impeccable timing Ford shot the toy arrow across its path. The arrow flew across the corridor and stuck, wobbling, on the opposite wall. As it flew, the robot’s sensors locked on to it instantly and the robot twisted through ninety degrees to follow it, see what the hell it was and where it was going.
This bought Ford one precious second, during which the robot was looking in the opposite direction from him. He hurled the towel over the flying robot and caught it.
Because of the various sensory protuberances with which the robot was festooned, it couldn’t manoeuvre inside the towel, and it just twitched back and forth without being able to turn and face its captor.
Ford hauled it quickly towards him and pinned it down to the ground. It was beginning to whine pitifully. With one swift and practised movement, Ford reached under the towel with his No.3 gauge prising tool and flipped off the small plastic panel on top of the robot which gave access to its logic circuits.
Now logic is a wonderful thing but it has, as the processes of evolution discovered, certain drawbacks.
Anything that thinks logically can be fooled by something else which thinks at least as logically as it does. The easiest way to fool a completely logical robot is to feed it the same stimulus sequence over and over again so it gets locked in a loop. This was best demonstrated by the famous Herring Sand- wich experiments conducted millennia ago at MISPWOSO (The MaxiMegalon Institute of Slowly and Painfully Working Out the Surprisingly Obvious).
A robot was programmed to believe that it liked herring sandwiches. This was actually the most difficult part of the whole experiment. Once the robot had been programmed to believe that it liked herring sandwiches, a herring sandwich was placed in front of it. Whereupon the robot thought to itself, `Ah! A herring sandwich! I like herring sandwiches.’