The night lights of Tokyo’s Marunouchi district shimmered off the sides of the Tokiwabashi Tower, rising between the railyards at Tokyo Station and the bustling Nihonbashi River. Less than five years old and nearly four hundred meters tall, it was the tallest building in Japan that still housed businesses after the earthquake and the war.
But the drone that circled the tower now paid little attention to the building itself. It used the structure’s many air traffic control transmitters to plot a safe flight path, but most of the drone’s active sensors were directed downward, watching the city.
Visible-spectrum images were of limited usefulness in the predawn darkness, when glowing billboards and advertising flashes drowned out any other light sources. But the drone’s other pickups—infrared, radar, sound—provided a rich survey of urban activity.
It was a deluge of data, but the drone had only been programmed to observe, not analyze. Later, maybe, it would learn how to scan for specific crime signatures: the sound of breaking glass, vehicles coming to sudden stops outside traffic lanes, human-sized heat blooms moving faster than average pedestrian speed. From this height, the drone could detect many things.
Unfortunately, it was not looking up when the man hit it.
The drone’s gyroscopes registered a massive disturbance, and though its thruster output spiked to 150 percent to counteract the downward motion, the weight of an adult human in free fall was far more than the compact field reconnaissance UAV had been engineered to withstand.
In less than two seconds, the drone was crushed against the pavement, flattened by the corpse tangled in its upper guidance fins.
The last bits of data it recorded included audio of what sounded like screaming.
Emma Higashi didn’t like people messing with her stuff. Even if the stuff in question was the remains of a drone that had apparently been crushed by a human body falling from a skyscraper.
Miyako made it through the police cordon first, and Emma jogged to catch up to her partner. A crime scene technician knelt over the well-dressed corpse that lay facedown in the middle of the street. More police stood at the building’s entrances and exits, conferring with the tower’s security guards.
“Konbanwa, Sato-san,” Miyako said to the tech.
“Konbanwa, Koreda-san,” Sato replied. He looked familiar, but Emma couldn’t quite place him. She had been meeting a lot of new people recently.
“The building is secure?” Miyako indicated the guards.
Sato nodded. “Until our investigation is concluded.”
Miyako gestured at Emma, then continued in English. “You remember Lieutenant Higashi Emma. My partner. She’s joined us from the American peacekeeping detachment. Emma, Investigator Sato is one of the Tokyo Metropolitan Police Department’s best forensics experts.”
Emma nodded, appreciating the reminder. “Konbanwa, Sato-san. That’s my drone you’re scraping off the sidewalk there, by the way.”
Sato raised an eyebrow. “Thank you, Lieutenant. I did not recognize the model, but I am not very familiar with American military hardware.” He hesitated. “May I ask why your drone was flying so close to the Tokiwabashi Tower?”
“It’s a long story. Do you want to tell us about the dead guy?”
Sato glanced at Miyako. “With respect, Lieutenant, we need to collect all information that may be relevant to this investigation.”
Emma noticed Miyako shifting her weight from one foot to the other. She had come to recognize this as a signal of unease, and Emma did want to stay on good terms with her partner.
“It was a test run of some new software,” Emma said. “We—the US—have a fair number of drones sitting in inventory here in Tokyo. I suggested we activate more of them to help support crime-fighting efforts. Passive surveillance only,” she added quickly when she saw Sato’s face souring. Many Japanese were still wary of foreign drones after how the Chinese had used them during the recent conflict, and how they continued to deploy them now during the occupation. “And we’re working with Tokyo police every step of the way. We’re here to help.”
“I see.” Sato sounded dubious. “How high was this drone programmed to fly?”
“One hundred meters, give or take, depending on wind conditions,” Emma said. “I might be able to pull some data off the drive.”
“Can you show our team how to do that?” Sato asked.
“It’s encrypted. You won’t be able to access anything without my security keys.”
“I will take charge of the evidence,” Miyako said. “We will follow police protocol.”
That seemed to satisfy Sato. “Of course, Koreda-san. As soon as we have...