This is a [SerialStory] with tags [SS] and [Subm] titled 'Submersible.'

Submersible is unique to Stacker News. SN is like Reddit, but with Bitcoin zaps instead of up and downvotes. Post articles, discussions, links, images, videos, and comment on them. Zap sats to the authors you appreciate. Don't worry if you don't have any Bitcoin sats, you can post for free for awhile until you earn some! Sign up now with this link -- it's free.

( Here is a link to part #1 so you can start at the beginning. )

( Find other items in the series - search 'Subm' | Find part 3 - search 'Subm_3' | Find other serials on SN - search 'SS_' )

Rebecca looked to her husband Kevin, who thought for a moment and shrugged that he did not. Then he turned back to her, and she conveyed: "Be our guest."

"Certainly." Thiago brought out the fob he'd been given by concierge upon arrival and considered his words before he began. "One button is ergonomically obvious. It was all but certain to remotely summon Forenza's employees -- as confirmed when Thaddeus pressed it." He acknowledged Thaddeus Tilney and motioned toward the cybernetic hostess idling nearby. "The second button is also obvious. It is colored brightly to indicate that it is to be used in emergencies...but the third button?" The engineer smiled, savoring his audience's anticipation, and then teasing them with it: "The third button has no evident purpose. So we must guess."

Thiago Vasquez turned the object slowly in front of him as if considering it for the first time; he made it a central focus for all who heard him. "What do we know about this device? We know that it sends a signal when a button is pressed." Then he asked, "What else?" and then, he began to answer. "The most obvious exploration is as to whether the device might be a receiver as well. But for what, and from where, would it receive?" He furtively paced the landing in front of the painting at the head of the staircase, gathered his thoughts, then began to paint the air with his arms in animated storytelling, using the curiosity of the others as his medium.

"By logic and pragmatics, we could assume at least one receiving function for this device: to confirm that summons or emergency signal was received by the hosts -- or by the system to which both they and the device are connected. Indeed, we watched together as Thaddeus summoned this robot host, and a visible green LED lit up the side of the device. Now. Perhaps that light is only a local indicator that the button's switch was triggered. But more likely, it is a true indication that a signal has been successfully transmitted and received."

Thiago paused and looked at each listener in turn. "Could that be all this device does? Is the third button really just another simple switch with a single function? One click, one beep?" Thiago paced a few steps, a bit thoughtfully, and a bit histrionically. Then he spun around and stepped purposefully back toward the group.

"Well let me ask you this... does Forenza Estates seem like the kind of place that would hand out... GARAGE DOOR OPENERS??!!"

The group exchanged glances that silently acknowledged their suspenseful enjoyment -- the Bosemans more for the entertainment, and Thaddeus more for the tantalization. Thiago Vasquez was on a roll.

"What simple addition to this object would grant Forenza's guests something more than just another single function?" His tone and expression begged a response.

"I can think of nothing more that we've seen or been told that gives us any particular clue," said Rebecca.

"And I agree!" Thiago responded. "With no further information provided to us, we must consider the context of our surroundings in combination with prior knowledge and common sense." A momentary pause offered their imaginations space to guess further before he hinted: "Think of the old multi-function devices we had before personalized wearables."

"I've got it!" Thaddeus interjected sarcastically, "It makes 'phone calls.'" The Bosemans smiled nostalgically while Vasquez proceeded unabated.

"Not phone calls, Thaddeus, but you're on to something, my friend. Depending on itinerary and activity, a simple blinking light would not suit the necessities of this context. Anything beyond an indication that dinner is ready would require more than that." More than one listener was reminded of their own hunger then.

"When Thaddeus pressed first, he received no audible confirmation through the device. However, that alone does not rule out the possibility of a speaker within. And look at this place. The ability to send a voice announcement to everyone, no matter where they are, might well be needed."

"And when we think of speaker, we must think of microphone," Tilney provided.

Thiago lit up, "Precisely! As was the case with the smartphones we used to carry, the vocal receiver can leverage natural languages that the user already knows so that any number of built-in commands can live alongside an intuitive extensible set, right out of the box. These devices, being handed to us at arrival, would not yet be paired to us as our personal wearables are. A microphone, therefore, is a nearly costless addition that opens up infinite possibilities!"

He brought his presentation, and their attention, to a denouement: "And look around you... Forenza Estates is infinite possibilities!"

The Bosemans were happy to survey the room once more, and saw that this was true.

Thiago spent the last of his attention in a feigned anti-climactic conclusion. "That is why I spoke into the fob."

"But it didn't work!" Thaddeus objected, losing patience.

Vasquez sprung his rhetorical trap and deftly recovered the suspenseful moment with a single prideful noise: "Aha!" Then he punctuated the final moment with dramatic flourish. "It is true. But then I knew!"

Thiago Vasquez began to reveal his conclusion: "It requires Voice... and... Action!" Then, after a brief moment to await any recognition that might occur unprompted, he finished: "Simultaneously pressing the third button is required to indicate that a word or phrase is a command, rather than part of normal conversation."

Thaddeus perked up as though he had an idea that might heal his shoulder. "Not so fast, Thiago. Allow me to challenge you with a bit of your own style of logical reasoning. Why would a guest need any device at all? Anything done through the three buttons, or any announcement that might be needed, could easily be done through antique intercoms placed throughout the buildings. You are stuck in an era before 'Hey Siri,' or 'OK Google.'"

"Well let us remove any doubt," Thiago replied with guile. He made a show of holding the third button as he spoke into the fob: "Flashlight!"

An LED at the front of the fob illuminated the space before it, finally giving Thiago the satisfaction of being proven. "Off," he said, and it obeyed.

"Oh Bullshit," Thaddeus frowned, "You get the same damn thing with an intercom and a complimentary flashlight."

Thiago had something yet up his sleeve, and was enjoying that effect on Tilney's natural contrarianism. He continued: "Now that we know the combination, we will see that this multi-function device will also... Open the doors!"

The lights in the Great Room dimmed halfway to showcase the brightly lit dining area that was revealed when the doors slid silently away. With space for everyone and view to a starlit sky over the ocean, existing conversations cleared the air, and initial confusion receded, as the crowd made their way to the stairs.

Please consider zapping this post if you enjoyed it. Much appreciated ~

WHAT DOES THIAGO KNOW? WHY NOT INTERCOMS? - Answer in the comments below. First correct answer wins the bounty.

Note: Part #5 had two bounties. #1 was not solved, and #2 was won by @cryotosensei for offering 'Robotics Engagment Declarations' as an idea for what R.E.D. should stand for. Perfect and better than anything I had thought of! Great ideas as to what the solution to #1 were offered, and much appreciated. Consolation prizes will be awarded :D Thanks~