nd I'm willing to admit that they are
wellnigh perfect. Such slight mistakes as sending men to South Africa
and Australia where the crops are six months later than the European and
American harvests may be forgiven, because the German thinks
longitudinally, and north and south are the two points of the compass
which he never bothers his head about. If the Germans had been a
seafaring people they'd have discovered America before Columbus, but
they would never have found the North Pole or rounded the Cape in a
million years."

He paused, and they saw the flicker of a smile in his weary eyes.

"The whole scheme is under van Heerden's hand. At the word 'Go'
thousands of his agents begin their work of destruction--but the word
must come from him. He has so centralized his scheme that if he died
suddenly without that word being uttered, the work of years would come
to naught. I guess he is suspicious of everybody, including his new
Government. For the best part of a year he has been arranging and
planning. With the assistance of a girl, a compatriot of his, he has
reduced all things to order. In every country is a principal agent who
possesses a copy of a simple code. At the proper moment van Heerden
would cable a word which meant 'Get busy' or 'Hold off until you hear
from me,' or 'Abandon scheme for this year and collect cultures.' I
happen to be word-perfect in the meanings of the code words because van
Heerden has so often drummed them into me."

"What are the code words?"

"I'm coming to that," nodded Milsom. "Van Heerden is the type of
scientist that never trusts his memory. You find that kind in all the
school--they usually spend their time making the most complete and
detailed notes, and their studies are packed with memoranda. Yet he had
a wonderful memory for the commonplace things--for example, in the plain
English of his three messages he was word perfect. He could tell you
off-hand the names and addresses of all his agents. But when it came to
scientific data his mind was a blank until he consulted his authorities.
It seemed that once he made a note his mind was incapable of retaining
the information he had committed to paper. That, as I say, is a
phenomenon which is not infrequently met with amongst men of science."

"And he had committed the code to paper?" asked Kitson.

"I am coming to that. After the fire at the Paddington works, van
Heerden said the time had come to make a get away. He was going to th