authorities. Peter once discussed with me the question of
disguises, and he had a theory which struck me at the time. He said,
barring absolute certainties like fingerprints, mere physical traits
were very little use for identification if the fugitive really knew his
business. He laughed at things like dyed hair and false beards and
such childish follies. The only thing that mattered was what Peter
called 'atmosphere'.

If a man could get into perfectly different surroundings from those in
which he had been first observed, and--this is the important
part--really play up to these surroundings and behave as if he had
never been out of them, he would puzzle the cleverest detectives on
earth. And he used to tell a story of how he once borrowed a black
coat and went to church and shared the same hymn-book with the man that
was looking for him. If that man had seen him in decent company before
he would have recognized him; but he had only seen him snuffing the
lights in a public-house with a revolver.

The recollection of Peter's talk gave me the first real comfort that I
had had that day. Peter had been a wise old bird, and these fellows I
was after were about the pick of the aviary. What if they were playing
Peter's game? A fool tries to look different: a clever man looks the
same and is different.

Again, there was that other maxim of Peter's which had helped me when I
had been a roadman. 'If you are playing a part, you will never keep it
up unless you convince yourself that you are it.' That would explain
the game of tennis. Those chaps didn't need to act, they just turned a
handle and passed into another life, which came as naturally to them as
the first. It sounds a platitude, but Peter used to say that it was
the big secret of all the famous criminals.

It was now getting on for eight o'clock, and I went back and saw Scaife
to give him his instructions. I arranged with him how to place his
men, and then I went for a walk, for I didn't feel up to any dinner. I
went round the deserted golf-course, and then to a point on the cliffs
farther north beyond the line of the villas.

On the little trim newly-made roads I met people in flannels coming
back from tennis and the beach, and a coastguard from the wireless
station, and donkeys and pierrots padding homewards. Out at sea in the
blue dusk I saw lights appear on the ARIADNE and on the destroyer away
to the south, and beyond the Cock sands the bigger l