He moved the well slide from side to side, bringing different parts of the drop under his lens. There was a tiny wisp of vegetable matter he recognized as a dead bit of Riccia, and a few black threads of algae.
Rick shook his head in bewilderment. "Whatever the Blue Ghost is," he stated, "it's a killer. The mob we saw is gone."
Dr. Miller took over the instrument and confirmed Rick's findings. "The water is dead," he said at last. "I don't know how useful it is to know that, but I can't imagine that a supernatural agency would bring death to millions of microscopic creatures. Yet, if it isn't supernatural, how is it done and who does it?"
"I've never seen such hard people to convince of anything," Barby declared. "All the evidence points to a real ghost, it seems to me. But you keep trying to prove something else and you don't get very far."
"We get as far as dead water and radioactive cement bags that don't contain cement," Rick pointed out. "For a while tonight I was about convinced that the ghost was supernatural, but I'm still going to be a doubting Thomas, at least until we run all leads into a dead end!"
CHAPTER XIII
The Night Watchers
Rick couldn't sleep. He kept trying for a comfortable position, but the hitherto excellent bed suddenly seemed full of lumps. His pillow wouldn't behave, either. It seemed determined to lump up and deprive him of sleep.
His body was tired enough, but his mind kept worrying the problem of the Blue Ghost endlessly, going over incidents and details, searching for a meaning, a clue that would lead to a conclusion.