 Why does the block tower fall down?
Nobody's been able to get near him for three weeks, and now at six o'clock this morning he decides he's leaving the Farm. The first was from Roberts Bros., announcing another shift of deadline on the book, and demanding the galley proofs two weeks earlier than scheduled. And the more they struggled, the thicker and more impenetrable the bramble bush became— But now David Lessing had discovered a pathway through that jungle, a theory to work by— At his elbow the intercom buzzed. "Until we had to throw it out. "Only took them seventy years to climb it, thanks to a certain man's theories. Just as the ability to think logically in a crisis instead of giving way to panic is a differentiating quality."
 Unknown. It is too early in the field of psi research to accurately determine the answer.
 Lessing removed his helmet.  The children used their psi powers to influence Lessing into removing his helmet.  The children removed their helmets.  Unknown. It is too early in the field of psi research to accurately determine the answer.