Morrow took the oversize box into the storeroom and came out with the prism. He set it up in a carrel for the third customer with seconds to spare. At four o’clock, the ready lights on all three prisms came on, and all three customers began chatting with their paraselves.
Nat followed Morrow into the office behind the front counter. He took a seat at the desk as if nothing had happened. “Well?” she asked. “What took you so long?”
“I was talking to one of the aides at the home.” Morrow had just come back from seeing one of their customers. Jessica Oehlsen was a widow in her seventies with few friends and whose only son was more of a burden than a comfort. Almost a year ago she’d started coming in once a week to talk with her paraself; she always reserved one of the private booths so she could use voice chat. A couple months ago she had fractured her hip in a bad fall, and now she was in a nursing home. Since she couldn’t come to the store, Morrow brought the prism to her every week so she could continue her regular conversations; it was a violation of SelfTalk’s company policy, but she paid him for the favor. “He filled me in about Mrs. Oehlsen’s condition.”
“What about it?”
“She’s got pneumonia now,” said Morrow. “He said it happens a lot after a broken hip.”
“Really? How does a broken hip lead to pneumonia?”
“According to this guy, it’s because they don’t move around a lot and they’re zonked on oxy, so they never take a deep breath. Anyway, Mrs. Oehlsen’s definitely got it.”
“Is it serious?”
“The aide thinks she’ll be dead within a month, two tops.”
“Wow. That’s too bad.”
“Yeah.” Morrow scratched his chin with his blunt, square fingertips. “But it gave me an idea.”
That was no surprise. “So what is it this time?”
“I won’t need you on this one. I can handle it by myself.”
“Fine by me. I’ve got enough to do.”
“Right, you’ve got a meeting to go to tonight. How’s that going?”
Nat shrugged. “It’s hard to tell. I think I’m making progress.”
Every prism—the name was a near acronym of the original designation, “Plaga interworld signaling mechanism”—had two LEDs, one red and one blue. When a prism was activated, a quantum measurement was performed inside the device, with two possible outcomes of equal probability: one outcome was indicated by the red LED lighting up, while the other was indicated by the blue one. From that moment forward, the prism allowed information transfer between two branches of the universal wave function. In colloquial terms, the prism created two newly divergent timelines, one in which the red LED lit up and one in which the blue one did, and it allowed communication between the two.
Information was exchanged using an array of ions, isolated in magnetic traps within the prism. When the prism was activated and the universal wave function split into two branches, these ions remained in a state of coherent superposition, balanced on a knife’s edge and accessible to either branch. Each ion could be used to send a single bit of information, a yes or a no, from one branch to the other. The act of reading that yes/no caused the ion to decohere, permanently knocking it off the knife’s edge and onto one side. To send another bit, you needed another ion. With an array of ions, you could transmit a string of bits that encoded text; with a long-enough array, you could send images, sound, even video.
The upshot was that a prism wasn’t like a radio connecting the two branches; activating one didn’t power up a transmitter whose frequency you could keep tuning into. It was more like a notepad that the two branches shared, and each time a message was sent, a strip of paper was torn off the top sheet. Once the notepad was exhausted, no more information could be exchanged and the two branches went on their separate ways, incommunicado forever after.
Ever since the invention of the prism, engineers had been working to add more ions to the array and increase the size of the notepad. The latest commercial prisms had pads that were a gigabyte in size. That was enough to last a lifetime if all you were exchanging was text, but not all consumers were satisfied with that. Many wanted the ability to have a live conversation, preferably with video; they needed to hear their own voice or see their own face looking back at them. Even low-resolution, low-frame-rate video could burn through a prism’s entire pad in a matter of hours; people tended to use it only occasionally, relying on text or audio-only communications most of the time in order to make their prism last for as long as possible.
Dana’s regular four o’clock appointment was a woman named Teresa. Teresa had been a client for just over a year; she had sought out therapy primarily because of her difficulty in maintaining a long-term romantic relationship. Dana had initially thought her issues stemmed from her parents’ divorce when she was a teenager, but now she suspected that Teresa was prone to seeking better alternatives. In their session last week, Teresa had told her that she had recently run into an ex-boyfriend of hers; five years ago she had turned down a marriage proposal from him, and now he was happily married to someone else. Dana expected that they would continue talking about that today.
Teresa often started her sessions with pleasantries, but not this time. As soon as she sat down she said, “I went to Crystal Ball during my lunch break today.”
Already suspecting the answer, Dana asked, “What did you ask them about?”
“I asked them if they could find out what my life would look like if I had married Andrew.”
“And what did they say?”
“They said maybe. I hadn’t realized how it worked; a man there explained it to me.” Teresa didn’t ask if Dana was familiar with it. She needed to talk it through, which was fine; she was often able to untangle her thoughts that way with only slight prompting from Dana. “He said that my decision to marry Andrew or not didn’t cause two timelines to branch off, that only activating a prism does that. He said they could look at the prisms they had that had been activated in the months before Andrew proposed. They would send requests to the parallel versions of Crystal Ball in those branches, and their employees would look up the parallel versions of me and see if any of them were married to him. If one of me was, they could interview her and tell me what she said. But he said there was no guarantee that they’d find such a branch, and it cost money just to send the requests, so they would have to charge me whether they found one or not. Then, if I want them to interview the parallel version of me, there’d be a separate charge for that. And because they’d be using prisms that are five years old, everything would be expensive.”
Dana was glad to hear that Crystal Ball had been honest about their claims; she knew there were data brokers out there that promised results they couldn’t deliver. “So what did you do?”
“I didn’t want to do anything without talking to you first.”
“Okay,” said Dana, “let’s talk. How did you feel after the consultation?”
“I don’t know. I hadn’t considered the possibility that they might not be able to find a branch where I said yes to Andrew. Why wouldn’t they be able to find a branch like that?”
Dana considered trying to lead Teresa to the answer herself, but decided it wasn’t necessary. “It could mean that your decision to reject him wasn’t a close call. It may have felt like you were on the fence, but in fact you weren’t; your decision to turn him down was based on a deep feeling, not a whim.”
Teresa looked thoughtful. “That might be a good thing to know. I wonder if I ought to just have them do the search first. If they don’t find a version of me that married Andrew, then I can just stop.”