"Take it easy," his father said. "We've got a little better picture of what we're up against. The dust is quite definitely from the comet's tail. It has a very large molecule, and is suspended in our atmosphere in colloidal form. Its basis is a transuranic element, which is, however, only slightly radioactive. By volume, it is present in the amount of about one part in ten million, which is fairly heavy concentration for an alien substance of that kind.
"Perhaps the most important thing we've found is that it has a strong affinity for metals, so that its accumulation on metallic surfaces is much higher than in the general atmosphere."
"It would!" Ken said, with a vague attempt at humor. "Why couldn't it have had an affinity for old rubber tires, or secondhand galoshes?
"How late is it? Can I get up to the lab this afternoon?" Ken struggled to a sitting position. A gigantic pain shot through his head and down his spinal column. He felt as if his head were encased in a cement block. He fell back with a groan.
"Don't try that again for a few days!" his father said severely. "You're not going anywhere for quite a while. I have to go now, but your mother will be in tonight. Maria will come, too. You do what the doctors and nurses tell you to!"
"Dad—why am I here?" He moaned in agony of both spirit and body.
"You had an accident," said Dr. Adams smoothly. "It will all come back to you and you'll soon be fine."
Ken watched his father disappear through the doorway. He felt the sting of a needle in his arm and was aware the nurse was standing near. He wanted to talk some more, but suddenly he was too tired to do anything.
It came to him in the middle of the night, like a dark, wild dream that could be only the utmost fantasy. He remembered the silent, shapeless figures against the black wall of the old skating rink, and then he knew it wasn't a dream because he could remember clearly the words of Jed Tucker and his father. He could also remember Mr. Allen saying, "We can't let him go. Whoever he is, we've got to get him out of the way."