In the main office building they donned the close-fitting psionic monitors required of all personnel at the Farm. They were of a hard grey plastic material, with a network of wiring buried in the substance, connected to a simple pocket-sized power source. "The major problem," Lessing said, "has been to shield the children from any external psionic stimuli, except those we wished to expose them to. Our goal is a perfectly controlled psi environment. The monitors are quite effective—a simple Renwick scrambler screen."
"It blocks off all types of psi activity?" asked Melrose.
"As far as we can measure, yes."
"Which may not be very far."
Jack Dorffman burst in: "What Dr. Lessing is saying is that they seem effective for our purposes."
"But you don't know why," added Melrose.
"All right, we don't know why. Nobody knows why a Renwick screen works—why blame us?" They were walking down the main corridor and out through an open areaway. Behind the buildings was a broad playground. A baseball game was in progress in one corner; across the field a group of swings, slides, ring bars and other playground paraphernalia was in heavy use. The place was teeming with youngsters, all shouting in a fury of busy activity. Occasionally a helmeted supervisor hurried by; one waved to them as she rescued a four-year-old from the parallel bars.
They crossed into the next building, where classes were in progress. "Some of our children are here only briefly," Lessing explained as they walked along, "and some have been here for years. We maintain a top-ranking curriculum—your idea of a 'country day school' wasn't so far afield at that—with scholarships supported by Hoffman Center funds. Other children come to us—foundlings, desertees, children from broken homes, children of all ages from infancy on. Sometimes they stay until they have reached college age, or go on to jobs. As far as psionics research is concerned, we are not trying to be teachers. We are strictly observers. We try to place the youngsters in positions where they can develope what potential they have—without the presence of external psionic influences they would normally be subject to. The results have been remarkable."
He led them into a long, narrow room with chairs and ash trays, facing a wide grey glass wall. The room fell into darkness, and through the grey............