Ruthra finally found the bay, the badge blinked, signaling no access. A voice came over the speaker of the clearance system:

– Who are you?

– I'm here at Ruzi's request," Ruthra explained and introduced himself. – You can call me Dr. Rutra.

A few seconds later, the door opened. Behind the door, a man sat on a special device. He was an invalid, just as Ruzi had warned. He had something that looked like an outgrowth instead of legs. He had probably had polio as a child.

– I'm Dr. Gabo," he introduced himself, while looking intently at Rutra, "pausing" to study his eyes, then opening his own wide.

Ruthra realized what this was all about.

– Come in, just call me Gabo. Come with me.

He, sitting on something that looked like a cushion, pressed a button on a key fob that hung from his belt, the "cushion" moved it to the side, no leverage or hydraulics. It was a magnetic cushion rig, it literally floated in the air. Gabo pressed another button and "flew" forward.

– It's convenient with the button, you know exactly what you thought and duplicate it physically," he commented on the process, realizing that for someone who is allowed into such "holy of holies", it's backward technology.

Ruthra followed him. Soon they were in a room as empty and mirrored as all the corridors. Gabo pulled an object from his pocket that looked like a flashlight and inserted it into a hole in the floor. What happened next prompted Rutru to think that there was something else that could surprise him. Light "poured" from the flashlight, there was no other way to explain it. The blue light slowly began to illuminate and envelope Rutru and Gabo in a "dome". Soon the mirrored walls were no longer visible and neither were the floor and ceiling. They were inside the sphere.

– We've got half an hour before this gets suspicious. If anything, you and I were talking about the properties of the photoelectric effect. Alibis are important. I hope you don't get confused.

– Which one?

– The one that won Einstein the Nobel Prize.

– About the 3rd law of the photoelectric effect?

– All of them.

– Be more specific.

Ruthra asked for clarification, since Gabo had emphasized that the alibi was important. Rutra understood it himself, not quite realizing the essence of the meeting yet. And clarifications were needed, because the entire photoeffect was explained in 1905 by Albert Einstein on the basis of Max Planck's hypothesis about the quantum nature of light. For which, in 1921, he, thanks to the nomination of Swedish physicist Carl Wilhelm Oseen, received the Nobel Prize.

– It's not that hard to explain if the discovery has already been made," Gabo replied, thus making it clear that he understood the "topic", and at the same time it was a "marker" for the reaction by which they began to understand "their topic".

– Well, that explains it, now for the main point," Ruthra said.

– Are you the scientist Ruzi warned me about?

– I guess. I don't know what she warned you about or when.

– She's known about your visit for a long time. What are you interested in?

– Encryption, decryption, masking of the signal source. Covert, top-secret dual-purpose installations that can be used for this purpose.

– Why would you do that?

– We picked up a signal that the coded system accepted as valid.

– So what?

– This system is the Perimeter Program. Do you know about it?

– Oh, yeah. That's it?

Rutra didn't like that Gabo wasn't serious about what he said, so he decided to change the subject. As it turned out, it didn't work.