Chapter 18: Multipath Problem
Timeline: 08:00, 1 day after IoT Test
Location: The Barn & Agonwood Test Track, GIG/Apex R&D Campus, Agonwood
"Again," Julian commanded over the radio.
On the main monitor, the telemetry from the black sedan was a mess of red jagged lines. Marcus was driving the test vehicle in tight loops around the perimeter of the campus, accelerating and braking in a rhythm designed to induce maximum signal noise.
"We're getting nothing but static," Dave said, rubbing his eyes. "As soon as he hits thirty miles per hour, the signal-to-noise ratio inverts. The motion of the vehicle creates too much interference for the mesh to isolate the background entropy."
I watched the screen, chewing on the end of a stylus.
"It's multipath interference," I said. "We're moving the receiver through a landscape of reflections. The Wi-Fi signals bounce off the ground, the trees, the buildings. As he moves, he's driving through thousands of interference patterns every second."
"Rayleigh fading," Dave muttered. "The signal strength is bouncing up and down because of his physical position."
"Exactly. To the algorithm, that rapid fluctuation looks like high entropy. It looks like the noise we're trying to measure."
"So the faster he goes, the blind spot gets bigger," Dave summarized.
I nodded.
"Again," Julian repeated into the mic, ignoring our analysis.
"Julian, stop," I said, reaching over and keying the mic. "Marcus, bring it in. We're just burning tires at this point."
"Copy that," Marcus's voice came back, sounding relieved. "I was about to ask for a barf bag anyway."
The sedan drifted into the open bay doors of The Barn a minute later, heat radiating from the brakes. Marcus climbed out, looking slightly pale.
"Did we get it?" he asked.
"We got a terabyte of garbage," Julian said, stepping down from the platform. He looked at me. "Fix it."
"I can't fix wave mechanics, Julian," I said, pulling up the raw data logs. "If the receiver moves through a scattered field, the amplitude fluctuates. That is a fundamental law of radio physics."
"Then filter it," Julian said. "You know the speed of the car. You know the statistical model of the fading. Do the math."
I stared at him. He made it sound like an arithmetic problem from a third-grade textbook.
"He's right," Dave said slowly.
I looked at Dave. "You're siding with him?"
"No, I mean... literally," Dave pointed to the screen. "We have access to the car's CAN bus. We know the exact velocity and acceleration of the vehicle in real-time. We can feed that telemetry into the algorithm."
"Dynamic thresholding," I realized. "If the car is stopped, the algorithm expects zero variance. If the car does sixty, the algorithm expects high variance."
"We tell the system to ignore the 'road noise' caused by the speed," Dave said. "We only flag it if the signal gets cleaner than the speed should allow."
"It would have to be fast," I warned. "Millisecond latency. The correlation has to be perfect."
"We have the processing power," Dave said, glancing at the wall of servers. "I can link the car's speedometer directly to the patch."
"Give me an hour," Dave said, cracking his knuckles.
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Timeline: 11:00
Location: The Barn
"Patch 3.2 is live," Dave announced. "I've hardwired the car's telemetry into the detection unit. The algorithm now adjusts the entropy baseline dynamically based on wheel speed."
"Let's test it," Julian said.
"I'll drive," I said, grabbing the keys from the bench.
"You?" Julian raised an eyebrow. "Marcus is the trained driver."
"Marcus is currently turning a shade of green that clashes with the floor," I pointed out. Marcus gave me a grateful thumbs-up from where he sat near a fan. "Besides, I need to see the data stream in the car. I need to know how it feels."
"I'm coming with you," Julian said.
"Shotgun," Dave called out, grabbing his laptop.
We piled into the sedan. I adjusted the seat—Marcus was significantly taller than me—and tapped the screen on the dashboard where Dave had mirrored the sensor data.
"Ready?" I asked.
"Go," Julian said from the back seat.
I punched the accelerator. The electric motors whined, and we shot out of The Barn onto the service road.
"What's your speed?" Dave asked, eyes glued to his laptop.
"Forty," I said. "And we're approaching the cul-de-sac." I watched the dashboard. The blue line of the entropy monitor wavered, spiking slightly as we accelerated, but then it leveled out. The algorithm was eating the road noise.
"It looks like the compensation is holding," Dave said. "The multipath noise is filtered."
"Faster," Julian ordered.
I pushed it to sixty. The trees blurred. We swept past the perimeter fence of the test zone.
"Passing Unit 6," I called out.
On the screen, the blue line dropped. It plunged from the noisy baseline into a flat, silent valley.
SIGNAL INTEGRITY: 99.8%
"We have a hit!" Dave yelled. "It registered the leak at sixty miles per hour!"
I slammed on the brakes, bringing the car to a screeching halt at the end of the service road. "It works," I breathed, looking at the data log. "The math holds."
"We have a mobile detector," Julian said, leaning forward between the seats to look at the screen. He was close enough that I could smell the oud wood scent. "We can map the entire county."
"We can map the world," Dave corrected. "As long as we have a car and a cell signal."
I looked at Julian in the rearview mirror. He was already calculating.
"Alex needs to know," Julian said. "Get us back to the lab."
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Timeline: 14:00
Location: The Barn
Alex arrived twenty minutes later, looking fresh from a board meeting. He stared at the data on the big screen—the clean, beautiful dip in the line representing a hole in reality detected from a moving vehicle.
"You did it," Alex said.
"Dave did the coding," I said. "I just did the math."
"And Julian did the yelling," Dave added helpfully.
"It's a team effort," Alex said, turning to me. "This changes the timeline. I want this software installed in my personal fleet by Monday. And I want a portable unit—something we can put in a backpack—by the end of the month."
"Backpack is harder," I warned. "We don't have the car's power supply or the stable telemetry to filter the movement. A walking person moves unpredictably."
"Variables," Alex said, repeating our conversation from dinner. "You'll solve them."
He checked his watch.
"But for now, we stop. Your friends arrive tomorrow."
I nodded. "Ellie and Dan."
"The Guest Suites are prepped," Alex said. "The fridge is stocked. And Julian sent me a menu for the welcome dinner that involves entirely too many courses."
"Feel free to pair it down. Elli and Dan would be good with chicken and beer," Marcus added.
I looked at Julian, who was back at his whiteboard, erasing my equations to make room for his own.
"He's actually going to cook?"
"He considers it a performance," Alex said softly. "Let him show off. It keeps him manageable."
Yes, but who is he performing for this time? I thought but couldn't bring myself to say out loud.
Alex turned to leave, then paused.
"Lonna. Take tomorrow off. Spend the day with your friends. Show them around. Let them see that you're happy here."
"I am happy here," I said, realizing it was true.
"Good," Alex said. "Because once we start mapping the world... I have a feeling we're going to find a lot more holes."
I leaned over and whispered to Dave, "He knows we already found some, doesn't he?
Dave nodded.
I giggled.
Alex walked out.
Julian was tapping the end of a closed dry erase marker on his lips while staring at me intently. I looked down and away.
"Lonna," Julian called out, but when I looked at him, he was simply smiling and tapping on the watch that displayed my biometrics.
I sighed and rolled my eyes.
Looking at the screen one last time, the blue line was steady. The math worked. The physics held.
For a moment, I allowed myself to believe that we could actually control this. That we could put the universe in a box and label it.
That maybe I was happy here.
Then I looked at Julian, staring at the whiteboard with that hungry intensity, and I remembered: Chaos always finds a way in.
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Timeline: 16:00, Friday
Location: GIG/Apex R&D Campus, Agonwood
"Stop pacing," Marcus said from the couch in Unit 3. "You're going to wear a groove in the laminate."
"I'm calibrating the floor sensors," I said, turning on my heel to pace in the other direction.
Marcus snorted. "They're going to love it, Lon. It's free luxury housing in the Bay Area. They're residents. They're used to sleeping in on-call rooms that smell like bleach and despair. This place is going to look like the Ritz to them."
"When did you go sniffing the hospital dorms, Marc? Do you need to tell me something?" Teasing Marcus was a way for me to get back into "friend-mode" to show that the move hadn't changed me to my good friends. But, I was nervous as hell.
I stopped at the window. The Guest Suites were visible across the central courtyard—a wide expanse of decomposed granite and pavers labeled "The Commons." It separated the staff rowhouses from the guest blocks. The landscaping was strictly xeriscaped: succulents, ornamental grasses, and olive trees that required minimal water.
"It's just… worlds colliding," I admitted. "West Virginia Lonna and Agonwood Lonna."
"There's only one Lonna," Marcus said, standing up and walking over to put a hand on my shoulder. "Just with better clothes now."
"Should I change back into my old clothes? I'm not at work right now…"
He tugged at the sleeve of my new navy blazer.
A silver Toyota RAV4 pulled up to the curb of Block B.
"They're here," I breathed and ran out the door before Marcus could stop me.
I made it halfway across the plaza when the driver's side door flew open.
"LONNA!"
Dan Nikaido didn't just step out of the car; he launched himself. He covered the distance between us in long, athletic strides, his face splitting into a grin that could power a small city.
Before I could even say hello, he scooped me up in a crushing bear hug and spun me around. My feet left the dusty gravel.
"Put me down, you giant!" I laughed, hammering on his shoulders.
"Never!" Dan declared, spinning once more for good measure before setting me down.
He kept his hands on my shoulders, looking me over with intense, energetic scrutiny. He looked exactly the same—messy dark hair, kind eyes, and the broad shoulders of a guy who spent his gym time lifting heavy things just to see if he could.
"Look at you!" Dan beamed. "You look… corporate! Is that a blazer? Who are you and what have you done with my sister's roommate?"
"She's still in there," Ellie said, stepping out of the passenger side. She looked exhausted but immaculate, her sharp bob cut perfectly framing her face. She adjusted her glasses and smiled—a cooler, calmer version of her twin.
"Hi, El," I said, pulling away from Dan to hug her.
"Hey, roomie," Ellie squeezed me back. "Nice digs. Alex Greyson really does have money to burn."
"You have no idea," I said.
Marcus jogged up, carrying a six-pack of beer he'd grabbed from the fridge.
"Hey, guys," Marcus said.
Dan released me and pulled Marcus into a bro-hug that involved a lot of back-slapping. "Marc! You traitor. You stole her, and you didn't even tell us the place came with a resort courtyard."
"It's mostly rocks and cacti," Marcus grinned. "But the beer is cold."
"Priorities," Dan agreed, taking a bottle.
He turned back to me, his energy shifting from playful to something warmer, more focused.
"Seriously, Lon," Dan said, stepping into my space again. "I missed you. The apartment is too quiet. Nephy isn't there to ignore me, and I have no one to watch bad sci-fi movies with."
"I missed you too, Dan," I said, feeling a pang of guilt for how little I'd thought about home in the last week.
"I brought you something," Dan said, his eyes lighting up. "I knew you'd be homesick, and I wanted to make a grand entrance."
He ran back to the car and opened the back hatch. He pulled out a massive, Styrofoam cooler taped shut with duct tape.
"Ta-da!" Dan announced, heaving it onto the pavers. "I stopped at the noodle shop right before we left. I packed four orders of the Spicy Miso Ramen in dry ice. It's probably frozen solid, but it's our noodles."
I stared at the cooler. It was ridiculous. It was sweet. It was… a problem.
"Dan, that's amazing," I said, genuinely touched. "But…"
"But what?" Dan asked, looking proud of himself. "We can heat it up tonight. Housewarming party. Noodles and beer, just like old times."
I looked at Marcus. Marcus winced.
"Actually," Marcus said, rubbing the back of his neck. "Tonight is… catered."
"Catered?" Ellie asked, raising an eyebrow.
"Sort of," I said. "My colleague… Julian. He insisted on cooking a welcome dinner."
"Julian?" Dan asked, his smile faltering slightly. "The guy who recruited you?"
"The guy who thinks he owns the place," Marcus muttered.
"That's because he literally does, Marc," I said, poking at him. "But Julian is making a thing of it," I explained quickly. "He wanted to impress you. It's kind of a performance."
Dan looked at the cooler, then at me. I saw the disappointment flash in his eyes, followed immediately by a competitive spark.
"Well," Dan said, hoisting the cooler onto his shoulder like it weighed nothing. "I guess we'll see if his cooking beats the Noodle Shop. Spoiler alert: It won't."
I giggled, stepping into the routine of spending time with my friends. I smiled and looked at Ellie and Dan. Then I said to Marcus, loudly, "We get to keep them, right?"
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Timeline: 18:30
Location: The Patio / The Commons
Julian had transformed the communal patio.
Gone was the glamping vibe. He had brought in linens, actual silverware, and a terrifying array of prep bowls. He stood at the grill wearing a black apron over his dress shirt, looking like a conductor about to lead a symphony.
When we walked up—Dan carrying the cooler, Ellie looking skeptical, and me looking nervous—Julian didn't even look up from the steak he was searing.
"Timing," Julian said to the air. "You're three minutes late. The resting period for the Wagyu is precise."
He turned then, his grey eyes locking onto Dan.
He scanned Dan instantly—the height, the muscle, the "Golden Retriever" energy, the possessive proximity to me.
Julian smiled. It was the shark smile.
"You must be the twins," Julian said smoothly. "I'm Julian Vane."
"Dan," Dan said, setting the cooler down on the table with a heavy thud. He didn't offer a hand; he just crossed his arms. "Lonna says you're the idea guy."
"I'm the catalyst," Julian corrected, repeating the line he'd used on me. He gestured to the grill with a pair of tongs. "And tonight, I'm the chef."
"Nice apron," Dan noted. "Do you actually cook, or do you just wear the costume?"
Ellie choked back a laugh. Marcus looked at the sky, praying for patience.
"I own Ember & Vine," Julian said, his voice cool. "I imagine you haven't heard of it. We don't serve… whatever is in that styrofoam box."
"This," Dan said, patting the cooler, "is soul food. It's comfort. Something tells me you don't do 'comfort.'"
"Comfort implies stagnation," Julian countered, flipping the steak with a flourish. "I prefer excellence."
"Okay!" I interrupted, stepping between them. "Everyone, play nice. Julian, this smells amazing. Dan, we can put the noodles in my freezer for a rainy day."
"Does it ever rain here?," Dan asked, staring at Julian.
"It rains," Julian said, meeting his gaze. "When the conditions are right."
Alex arrived at that moment, carrying two bottles of wine and radiating peacekeeper energy.
"Welcome!" Alex said, shaking Dan's hand and charming Ellie instantly. "I'm Alex. I apologize for the theatrics. Julian takes his hobbies very seriously."
"I see that," Ellie said, eyeing the perfect grill marks on the vegetables. "Is he always this… intense?"
"Yes, and even more lately," Marcus whispered to her.
We sat down. The seating arrangement became a strategic nightmare.
Alex took the head of the table. Julian stayed by the grill to plate the food. Marcus sat on one side.
Dan immediately pulled out the chair next to me, scraping it loudly against the patio stones to claim the spot.
"So, Lonna," Dan said, draping his arm over the back of my chair, effectively boxing me in. "Tell me about the lab. Are you running the place yet? I assume you're smarter than all the guys in suits."
He looked pointedly at Julian's back.
"I'm just the help," I said, taking a sip of water. "It's… different than the university. The pace is faster."
Julian arrived with the first course. Scallops with a saffron reduction. He placed a plate in front of me first, then Ellie, then the men.
He stood behind my chair, lingering just a second too long as he explained the dish.
"Day boat scallops," Julian said, his voice low, right near my ear. "Hand-dived. Seared at 450 degrees for ninety seconds."
He looked at Dan and said, "Try not to use ketchup."
Dan stabbed a scallop with his fork. "I'm sure it's fine." He took a bite. I watched him. Dan chewed. He swallowed. He looked annoyed.
"It's good," Dan admitted grudgingly. "A little small."
"It's a tasting menu, Dan," I whispered. "There are five more courses."
"Five?" Dan looked at me, his eyes wide. "I'm going to starve. We should have heated up the noodles."
"We'll have noodles later," I promised.
"So, Dan," Julian said, taking his own seat opposite us. He swirled his wine, watching Dan's arm around my chair. "You're a resident at SF General. Emergency Medicine?"
"That's right," Dan said, puffing up his chest a bit. "Front lines. Gunshots, car crashes, overdoses. Real life."
"Chaotic," Julian noted. "High entropy. You patch people up and send them back out to get broken again."
"I save lives," Dan corrected sharply. "I don't just sit in a lab playing with theories."
"We're not playing," Julian said, his eyes cold. "We're solving the equation that puts them in your ER to begin with."
"Yeah?" Dan challenged. "And how does a fancy scallop solve a car crash?"
"Variables," Julian said. "Everything consists of variables. Even you."
"Okay!" Alex announced loudly, pouring more wine. "Ellie! Tell us about Stanford. Surgery, right? That's impressive."
As the conversation pivoted, I looked at Marcus. He gave me a sympathetic grimace. Then I looked at Dan, who was glaring at Julian. And Julian, who was dissecting Dan with his eyes like a specimen.
My two worlds were on a collision course, and we hadn't even gotten to the main course.
I looked over at Alex, who was smiling with his eyes. And then I realized the moment I saw Alex had arrived, I could breathe again.