Before the whiteboard, Shiori continued her calculations. The matching addresses in Hagi. The return address on the envelope. Ryuzo Shinozaki's death. She ran the probability of connecting them in a single line over and over. First calculation: 0.7%. Narrowing the variables: 0.4%. Refining further: 0.28%. Below 0.3%. (It's not coincidence.) Turning the marker cap between her fingers, Shiori traced where her thoughts were leading. This was a logical conclusion. Not emotion. The "reason to go again" was completely in place. Leaving a gap in her shift would cause trouble—that was also true. Part-time work was a contractual obligation; missing a shift would disadvantage the other party. So she'd go to work. That was all. (I'm not acting out of curiosity.) Shiori told herself that. Over and over. Still, when she got into bed before dawn, what she felt vaguely was the sensation of something that hadn't run in five years starting to move again. The gears' oil hadn't dried up, that was all. Nothing more, nothing less. ◆ Shiimiya Central Delivery Center—Shiimiya City, Miyuki-cho 1-9-3, the hub that Tokan Logistics uses to maintain a 72% delivery share in the city—was noisiest around seven in the morning. Locker doors opening and closing, the startup sound of Toucan Pads—the tablet terminals Tokan Logistics issued to all couriers, combining GPS, route guidance, and signature records in one—and someone making instant coffee. Shiori took it all in from a table by the wall while checking her delivery list. B-block assignment. Same area as last time. Fewer variables made calculations easier. It was when the coffee steam entered her field of vision that Shiori noticed something was wrong at the next table. A young man stood alone, holding a tablet with both hands, staring intently at the screen. At the map. No— (It's upside down.) The terminal was rotated 180 degrees. The map was inverted. Yet the young man had a face that said "I see." Complete certainty. Understanding. Arms crossed, nodding. Shiori returned her gaze to the list. (Irrelevant.) ◆ When the young man stood up saying "Alright, heading to C-block," Shiori pretended not to hear. She'd known from a single glance at the posted shift schedule that he was assigned to C-block. But she said nothing. She loaded her items into the cart and left the center. Miyuki-cho was quiet in the morning. Just like the week before, she passed through the shopping street lined with shuttered storefronts, then entered the narrow residential lanes. The autumn air hung low, and last night's rain still wet the stone pavement. The first delivery was to an apartment complex in Miyuki-cho 3-chome. She slipped a small envelope into the mailbox and pressed the completion record on her Toucan Pad. Thirty seconds. Shiori walked toward the next address. And at the corner, he was there again. The young man held a package, looking at his smartphone in front of the lane. Shiori averted her gaze and passed. (Just coincidence.) Second delivery done. Down the slope. A document envelope into a house mailbox. Walking again. Turning into a narrow lane, he was there again. This time looking up at the address sign, tilting his head. Shiori ignored him. Third delivery. A wooden apartment in Miyuki-minami 2-chome. She pushed the package into the mailbox beside the door and turned around— "Um, is this maybe Miyuki-kita?" The young man was standing there. Package in his arms, looking slightly pathetic. Shiori took a quick look at his face. Early twenties, tall, short neat hair, clean-looking. Eyes slightly round. Overall atmosphere of "not used to being scolded by people." "South." "Huh, south?" "Is it north you're looking for?" "Yes, Miyuki-kita—wait, how did you know?" Shiori was already walking. This was the third time. In front of the same already-delivered mailbox, a young man with a package appeared. Three coincidences weren't coincidence. Shiori calculated that far and turned on her heel. "Map's upside down." "Huh?" "Your terminal map. You were holding it backwards." The young man went completely still for three seconds. Then he looked at the terminal, checked the orientation, and slowly raised his face. His expression became "all mysteries solved." "—Ohhhhh that's it!" Shiori had already turned the next corner. ◆ "Really, thank you so much! Um, I kept thinking 'B-block is so huge,' you know? Why are there so many?" Shiori didn't respond. "Oh, I'm Naoki Sakaki. Just started this month—" "I see." Walking up the slope, Shiori kept her eyes on her feet. More precisely, she was observing the mud pattern on Naoki Sakaki's shoes as he walked diagonally behind her. The concentrated brown mud on the outside of his right foot matched the soil texture along the Miyuki River. His left heel— "Isn't delivery work fun?" "No." There was a pause. "...So, it's not fun, then?" "I can observe." That was true, so she said it. Time with people was minimum thirty seconds. But with each delivery, information flowed in—mailbox shape, the weight of mail inside, the number of umbrellas left at the entrance, shoe sizes and quantities. Not too much to process. Actually, just the right density. Naoki Sakaki thought for a moment, then said, "I see." "There are a lot of slopes around here." Shiori didn't answer. Instead, she took the shortest-route lane. No point in taking the long way. Sakaki followed silently. Not too close, not too far behind. In a distance that Shiori struggled to describe as "natural," but couldn't find another word for. ◆ The afternoon batch was heavier. Shiori scrolled through the next delivery list while pulling her cart. From Miyuki-cho through Shiimiya-minami 3-chome, arriving at Grand Veil Shiimiya—a twelve-story apartment building built as a remnant of the old Shiimiya New Town redevelopment, with sixty percent of residents elderly. Two consecutive deliveries: rooms 806 and 807. Elevator to the eighth floor. While checking her Toucan Pad in front of room 807's door, Shiori found an unusual envelope among the package bundle. A4-sized brown envelope. Thinner than the other packages. The address— "Grand Veil Shiimiya Room 806, Sachie Mihara" Shiori's gaze stopped. This envelope was mixed in with the 807 delivery bundle. Sachie Mihara was in 806, Ryuzo Shinozaki was in 807—next door to each other. The return address came into view. Shiimiya City... the rest was abbreviated. "Shiimiya City Hagi ○." The last character was smudged, unreadable. Standard procedure was to return it to the center. Processed as a misdelivery or sorting error. Take it back to the center, hand it to the staff. In that moment, Shiori's mind moved. —When returned to the center, would the envelope's contents be checked? Or not? If not, why not? If yes, who would check? Three seconds, Shiori stood there. This was against regulations. She knew that. But evidence, once lost, never comes back. Hagi. Tokan Logistics' headquarters address. An envelope with unknown sender to the room next to where Ryuzo Shinozaki's body was found. Shiori slipped the envelope deep into her bag. Then, as if nothing had happened, she pressed the intercom for room 807. "—Come in," a voice said. Signature received. Thirty seconds. Complete. ◆ "Your expression changed." When they exited the elevator and left the apartment building entrance, Naoki Sakaki said it. Shiori glanced at him for just a moment. "When did you notice?" "Right after we got off on the eighth floor. Your pace slowed down just a little." Shiori didn't answer. Sakaki didn't ask anything else. That silence felt strange to Shiori. Not "what happened?" or "are you okay?"—just walking beside her in silence. This young man seemed to naturally choose not to pry. Walking down the slope, Sakaki opened his mouth. "My father was a courier too, you know." Shiori listened while facing forward. "Same Shiimiya. For a different company, before Tokan existed." "You said 'was.'" "...Yes." That was all the answer was. The weight of past tense contained in that single word. Shiori didn't ask for more. Not because she didn't need to, but because—something judged that not asking was more appropriate. (Sentimentality.) She tried to categorize it that way, but it didn't work. Separate from the unease she felt about Ryuzo Shinozaki's death, something else was there now, near her chest. It had no name. Shiori had spent five years processing only emotions from mystery novels, so she was poor at classifying emotions that arose within herself. (Processing deferred.) ◆ At the intersection before the center, Shiori stopped. In her head, she was cross-referencing the envelope's address again. Sachie Mihara, room 806. Next to Ryuzo Shinozaki. The abbreviated return address. Hagi—if so, the same street as Tokan Logistics headquarters. The probability of coincidence was— "Sakurama." Shiori didn't respond. She didn't want to stop the calculation. A few seconds later, there was movement at the edge of her vision. Naoki Sakaki, who had started to move forward, stopped and came back. He stood beside Shiori without saying anything. Not rushing. Not asking why. Just there. Shiori couldn't explain what that was. But after about ten seconds, she naturally started walking. Sakaki followed. The center's lights were visible ahead. (For five years, I didn't know this feeling.) Someone being beside you. Not processed as information itself, but simply—as weight, as temperature, as presence—landing somewhere in her chest. It had no name yet. But it was there. ◆ She returned to her room just after seven in the evening. Shiori took the envelope from her bag. She pulled a light from her desk drawer and held the envelope up to it. The outline of the contents was indiscernible. Something like folded paper. Thin. Then her gaze narrowed on the abbreviated return address. "Shiimiya City Hagi ○"—the last character was smudged. Possibly handwritten rather than printed. Using a magnifying glass, she could see faint numbers beneath the smudged part. Small numbers. Four digits. Pressed into the paper fibers as if written with force. Cross-referencing with the coin lockers at Shiimiya Station South Exit—the coin lockers near the south exit ticket gate—the box number matched with some possibility. Shiori set the envelope gently on her desk. (I have to go out again.) She reached for the whiteboard eraser, then stopped. No need to erase. The calculation was already done. Probability exceeded the threshold. The next action was decided. Outside the window, Shiimiya's night continued. Within this city's delivery routes, an invisible net was strung. Shiori had taken hold of one end of that net and put it in her bag today.