"Tell me about diving," Ailanna asked brightly, her voice sounding as if she were really interested.  She and Hagen had just finished their breakfast at one of the city's oldest restaurants.  There was nothing really remarkable about the place except that it contained scenes no other world could offer.  All there at the same time were visitors, new settlers, middle settlers, old settlers, and (for all that anyone could show to the contrary) some of the explorers themselves.  These folk of different eras were walking, ordering, sitting and eating not only side by side but sometimes literally in each other's laps.  The interference was only psychic and esthetic, of course, not physical.  Meanwhile the robot waiters of several ages glided through each other, sharing space in aisles and kitchen.

Now Hagen and Ailanna were coming out of doors again, riding a smoothly lifting ramp up to the eternally fresh light of the surface.

"Better than that, I'll show you.  Do you want to try it right now?"

"Why not?"

Hagen selected their direction and they started walking.  He had fallen into a thoughtful silence, and at first Ailanna only waited for him to speak, meanwhile watching him with her artifically enlarged eyes, greenish and feline.  As they walked they both could hear the pulsar component of the triple system beating as sound; the sound of the pulsar came now from overhead, thick, soft and unobtrusive, paced at one-third the speed of a human heart.

"Hagen, perhaps you'd better tell me a little, at least, before we try."

He looked around him as if startled, and shook his head to rid it of broken thoughts.  Then he took Ailanna by the arm and smiled at her.  He said: "What is called diving, on Azlaroc, is a means of approaching the people and things that lie under the veils of the years.  Nothing can pierce the veils, of course, but diving stretches them.  And there is a deconvolution process involved, accomplished by the computer that's part of every diver's gear."

"Deconvolution?"

"Well, it means that your perceptions of veil-bound objects are enhanced, in the direction of what the computer thinks they ought to be.  With optimum performance from the system, the effective distortion caused by veils is reduced by a factor of approximately five."

"You say 'in the direction of what the computer thinks' - that sounds something like restoring an antique.  How do you know if you've got close to what the original was really like?"

"I suppose you don't."  Hagen gestured, the equivalent of a shrug.  "Actually it's quite accurate for the middle past, at least.  Say, back to the year '250 or thereabouts.  It lets one get close enough to settlers later than that time to see them more clearly, make photographs, talk to them."  And more than that, thought Hagen, Gods of Space, more than that!  But for the moment he said no more.