Joe said: "All the tricks but one, that were used on the plane I came
on, were the same kind of trick. They were all arrangements for getting
regular destructive items--bombs or rockets or whatever--where they
could explode and smash things. The saboteurs were adding destructive
items to various states of things. But there was one trick that was
different."
"Yes?" said the Major, on the telephone.
"Putting explosive gas in the CO_2 bottles," said Joe painstakingly,
"wasn't adding a new gadget to a situation. It was changing something
that was already there. The saboteurs took something that belonged in a
plane and changed it. They did not put something new into a plane--or a
situation--that didn't belong there. It was a special kind of thinking.
You see, sir?"
The Major, to do him justice, had the gift of listening. He waited.
"The pushpots," said Joe, very carefully, "naturally have their fuel
stored in different tanks in different places, as airplanes do. The
pilots switch on one tank or another just like plane pilots. In the
underground storage and fueling pits, where all the fuel for the
pushpots is kept in bulk, there are different tanks too. Naturally! At
the fuel pump, the attendant can draw on any of those underground tanks
he chooses."