The attendees somewhat noisily went into motion, picking their bags up off the floor and shuffling away from one another, clearing a space that grew larger and larger until they were standing around the edges of the court in a ragged oval. Sophia and Matilda had remained closer to the center, standing near midcourt. Matilda’s hands moved in front of her as she worked with some sort of virtual user interface that was only visible to her.

A graph-paper pattern appeared superimposed on the floor. “Just a test pattern,” Matilda said. “Now, the point cloud.”

In one instant, several million motes of green light appeared in the space above the tennis court.

Even though the points were all the same color, and not connected to each other, they were immediately recognizable to the eye as together representing a landscape. In some places, mostly around the edges, the green points were on the floor. In others, in the interior, they were perhaps waist high on a typical person’s body. So the general sense—once everyone had had a few minutes to walk around and view it from different angles—was that they were looking at a three-dimensional terrain map of an island or a continent, bounded all around by the sea, with high land in the middle.

“Ireland,” someone declared.

“Much too mountainous!” someone else scoffed. “Just possibly the Isle of Man? It has a mountain in the middle.”

“This is far larger than that, if you look at all the rivers, the mountain ranges,” said a third. “I’m going to say the North Island of New Zealand? Hard to tell unless we get a ladder and look straight down on it.”

“This is no place that exists on Earth,” said a man speaking in a mild tone of voice but with a calm authority that brooked no argument. Heads turned toward a bald-headed, shaggy-bearded man, who looked to be in his sixties. Through most of ACTANSS 3 he had made a habit of sitting quietly in the back of the room, sans wearable, sometimes paying close attention and sometimes humming to himself as his mind apparently wandered. Through most of the current presentation he had shown a kind of mildly amused boredom, as if finding the subject matter too infantile for words, but when the landscape had appeared in the middle of the room he had been galvanized, and had practically knocked one person over while striding through the point cloud to focus his attention on an interesting feature.

“Pluto’s correct,” Sophia announced. “This doesn’t match against any known—”

“There’s no way that it could. That is obvious by inspection,” Pluto announced.

Sophia turned to glance over her shoulder at the bemused Matilda and winked at her as if to say, I told you so! Then she said to Pluto, “Would you like to explain what you mean by that?”