a nurse and two doctors and an
elaborate oxygen-administering apparatus. The apparatus was wheeled out.
The nurse followed. The two doctors hurried after her. The American
colonel of the airport was standing by the bed on which Coburn lay,
fully dressed.

Coburn felt perfectly all right. He stirred. The American colonel said
sourly: "You're not harmed. Nobody was. But Major Pangalos got away."

Coburn sat up. There was a moment's bare trace of dizziness, and that
was gone too. Coburn said: "Where's Miss Ames? What happened to her?"

"She's getting oxygen," said the colonel. "We were rushed here from the
airport, sleeping soundly just like those Bulgarians. Major Pangalos
ordered it before he disappeared. Helicopters brought some Bulgarians
down, by the way, and oxygen brought them to. So naturally they gave us
the same treatment. Very effective."

The colonel looked both chastened and truculent. "How'd you know Major
Pangalos for what he was? He was accepted everywhere as a man."

"His eyes were queer," said Coburn. He stood up experimentally. "I
figured they would be, if one looked. I saw the foam suit that creature
wore up-country, when he wasn't in it. There were holes for the eyes. It
occurred to me that his eyes weren't likely to be like ours. Not
exactly. So I hunted up the real Dillon, and his eyes weren't like I
remembered. I punched him in the nose, by the way, to make sure he'd
bleed and was human. He was."

Coburn continued, "You see, they obviously come from a heavy planet and
move differently. They're stronger than we are. Much like the way we'd
be on the moon with one-sixth Earth gravity. They probably are used to a
thicker atmosphere. If so, their eyes wouldn't be right for here. They'd
need eyeglasses."

"Major Pangalos didn't--"

"Contact eyeglasses," said Coburn sourly. "Little cups of plastic. They
slip under the eyelids and touch the white part of the eye. Familiar
enough. But that's not all."

The American colonel looked troubled. "I know contact lenses," he
admitted. "But--"

"If the Invaders have a thick atmosphere at home," Coburn said, "they
may have a cloudy sky. The pupils of their eyes may need to be larger.
Perhaps they're a different shape. Or their eyes may be a completely
alien color. Anyhow, they need contact lenses not only to correct their
vision, but to make their eyes look like ours. They're painted on the
inside to change the natural look and color. It's very deceptive.