"He figured out that after a few of them got into our dimension, through some fluke or other, they found that they could spawn puppet-humans who would become vehicles for others of their breed. They come 'in' by route of birth. Perhaps, Jerry thought, a freak accident generations ago let just one of them into our world, and he put his foot in the door. Now there are multitudes of them here. What was the ratio Jerry calculated, Alec?"
"About seven to six in our favor," said Alec Talbot. "Of course, that was figured within an hour or so at Charing Cross Station. He didn't have a chance to make a real survey. They got him first."
"Yes, they got him. He was so shocked by his discovery that he didn't cover up fast enough, and they found out he could see them. They harried him all over half of England, and finally they tracked him down at the club and shot his guts out."
"He died in my arms," said Alec without expression.
"But Mister Wolfe was shot by men from Scotland Yard and bobbies, sir," protested Johnson.
"That's what they seemed to be, Johnson, to you. Jerry could see them truly. He knew they were the usurpers, using the husks of human beings as points of contact between our dimension and theirs."
Johnson coughed politely. "And this is the story he told Mister Talbot?"
"We do. Partly because it tallies up with a lot of queer things, partly because it explains a lot of others. But mainly because we all knew Jerry Wolfe, and he was as sane and decent a fellow as ever breathed tobacco smoke."
"He couldn't see all of their dimension, you understand. It was only where one of them had taken over a human body that the veil was thin enough to be pierced by his blast-warped sight. There was a sort of field of force or something around them, and he could see the beasts and their nearby background of silver lines that ran at an angle of about forty-five degrees. That was all. He killed the human parts of three or four of them, and although he couldn't touch the other-dimensional folk with his bullets, when their human puppets died they were relegated to their own world again. They faded out and vanished, he said. Their point of contact was obliterated."
"I see, sir. I begin to get the picture. These foreigners--" I could not help smiling at the word--"have been infiltrating our island by some means, using our bodies, you might say, as disguises. A dirty bit of business, sir, if I may say so."