Li Chi returned to the imperial palace in Chang’an with Gao Xining and the child, but the investigation into the incident at the Imperial Garden was still underway.

Zhang Tang, leading his men from the Court of Justice, had already questioned every person in the Imperial Garden at least twice over. Nothing new had surfaced. From this, Zhang Tang concluded that none of them were accomplices of the mysterious assassin — they had simply been exploited through a gap in security, with the killer having disguised himself as one of the Garden’s cooks. With Zhang Tang’s skill at interrogation, his judgment that these people were clean was as good as a certainty.

Yet Zhang Tang couldn’t shake the feeling that something was still off. The heart of it: why had the assassin planted poison without any intention of actually killing the Empress or the Imperial Prince?

Just as Zhang Tang was turning this over in his mind, Lian Xiwu arrived from Chang’an. He had volunteered to come — the Imperial Garden had been built under his supervision, and when something went wrong there, he dared not shirk even a shred of responsibility. Though in truth he really was blameless. The construction had been nominally under his charge, but once Chang’an was finished, he had been sent off to other duties. At one point he had even led troops to reinforce the northern border. He had never stayed on-site throughout. Day-to-day oversight had fallen to officials under him; he had only come by for inspections.

After meeting with Zhang Tang, Lian Xiwu had the whole case laid out for him, and decided to walk the Imperial Garden himself from end to end.

The official who had overseen the original construction was a man named Yan Meisheng — honest by nature, meticulous to a fault in his work. The incident had given a man like him a terrible fright. After petitioning the Emperor, he had come with every blueprint of the Garden in hand.

“The Imperial Guards and the Court of Justice have searched for dozens of li in every direction and found nothing,” Zhang Tang said, turning to Lian Xiwu. “My lord, it was only after exhausting those options that we petitioned His Majesty to have you bring the original construction plans. I want to go through them carefully — there may be some concealed location in the Garden where that criminal could be hiding. I’ve never quite believed he fled far.”

Yan Meisheng raised a hand to mop the sweat from his brow; he was so rattled he could barely string words together. “I’ve brought all the blueprints. You may have the Court of Justice look them over with me — but these plans are classified state secrets, since they concern His Majesty’s safety…”

Zhang Tang nodded. “Understood. I’ll put Fang Xidao — Fang Qianban — on it with you. We’ll keep the number of eyes on those plans to a minimum.”

“Thank you, my lord. Thank you.”

Yan Meisheng bowed over and over, a fresh layer of sweat breaking out across his forehead. Had Zhang Tang not already investigated him and known the man was simply built that way, that reaction alone might have looked suspicious.

The blueprints were numerous and dense with detail. Fang Xidao and Yan Meisheng worked through them for a long while without finding any thread to pull. It was Fang Xidao who finally thought of a different approach: instead of searching the plans directly, look for any temporary shelters the original builders might have excavated and then forgotten to fill in.

That prompted something in Yan Meisheng’s memory.

“Qianban, there’s something I just recalled.”

“For a project like this,” Yan Meisheng explained, “the standards were extraordinarily strict — not just within the Garden itself. To ensure the buildings inside would be free of geological hazards, the surveyors went dozens of li beyond the Garden’s perimeter, drilling sample cores everywhere.”

He looked at Fang Xidao. “There are a great many cellars that were dug across that whole area during those surveys — used to test whether the ground would collapse under vibration.”

Fang Xidao asked at once: “Are all those locations marked on the blueprints? Were they filled in afterward?”

Yan Meisheng hesitated. “That… probably… not all of them were filled back in. At the time it didn’t seem necessary, and besides, we were rushed off to other work elsewhere, so…” He hastily added: “But every location was noted down. Let me check — I’ll look right now.”

Before long, he had found the geological survey maps. Fang Xidao counted: there were dozens of test-excavation sites. He had little prior experience with such things, but after staring at blueprints for so long and now seeing the scope of these test digs, it finally sank in just how vast an undertaking it was to build an imperial garden for the royal family — how much labor and material it consumed.

Fang Xidao went immediately to Zhang Tang with the news. Zhang Tang listened, then ordered three of his *qianban* officers to each take a contingent of Black Cavalry and investigate separately, while also dispatching a messenger to inform Xia Houzhu, the Imperial Guards’ Grand General. The case involved the Imperial Guards, and Xia Houzhu had to be kept informed.

Xia Houzhu had not returned to Chang’an. The case nagged at him too — he couldn’t feel easy until it was solved. Upon hearing Zhang Tang’s report, he decided to personally lead five hundred Imperial Guard cavalry to check the sites.

Following the maps, Xia Houzhu led his horsemen to the first marked excavation — and found absolutely nothing. The ground was clear, without so much as a crack in the soil. According to Yan Meisheng, these test cellars had been dug to the same exacting specifications as the emergency shelters beneath the Imperial Garden itself — the kind of bolt-holes built so the imperial family would have somewhere to shelter in a crisis. They had to be capable of withstanding enormous pressure: after the internal timber and stone supports were installed, heavy carts and galloping horses were driven back and forth over the top, and massive stones were hoisted in rope cradles and suddenly dropped, to test whether the structure would hold. But when the tests were done, the sites had been left as they were. Admittedly that had been an oversight — though to be fair, the crews were already stretched thin, pulled away to help build structures inside Chang’an itself, including the Yan Tower Academy, which Yan Meisheng’s team had also supervised. That was in fact the work that had earned him a promotion to Vice Minister of Works.

Still, the absence of any visible depression where there ought to have been one made Xia Houzhu suspicious rather than relieved.

“Bring some drag-sleds back here,” he ordered. “I want this whole area swept, back and forth, until I’m satisfied.” He dismounted while he waited, found a spot to sit, and in the meantime ordered the rest of his men to dismount and advance in a line, shoulder to shoulder.

They never needed the sleds. One soldier in the sweeping line suddenly felt something wrong underfoot — a hollow sound. He called out immediately. The soldiers around him converged at once, weapons in hand.

Xia Houzhu strode over, took a long spear from one of his men, and tapped the suspicious patch of ground with the butt. The sound told him they had found it. He turned and barked: “Get dry kindling — now!”

He stood on the trapdoor holding it down with the spear, bracing against it while his men gathered wood. Before long the cover shifted — whoever was underneath was getting restless and trying to force their way out — but Xia Houzhu’s strength was extraordinary; one man was enough to keep the whole panel shut.

When an armful of kindling was ready, Xia Houzhu called down through the cover: “Come out quietly and I’ll let you live — for now. Stay put, and we light it. I doubt any of you want to find out what it’s like to choke to death on smoke.”

A moment of silence. Then muffled voices rose from below.

“We surrender! We had nothing to do with any of it — please don’t set fire!”

“Please, let us out — we won’t resist, just let us out!”

Xia Houzhu gestured for his men to step back and had the archers take aim at the trapdoor. He withdrew a pace, levered the cover up with his spear, and flung it aside.

One by one, figures crawled out of the cellar — grey with dirt and grime, which told the story of their time in that hole well enough. They reeked. Having been sealed in that enclosed space — eating, drinking, and doing everything else down there — they could hardly have smelled otherwise.

These brigands from Shu Province could do nothing but curse their luck. They hadn’t actually done anything, and now here they were, rounded up wholesale.

Meanwhile, back in Chang’an, a carriage bearing Xu Ji was making its way urgently toward the Weiyang Palace.

Xu Ji was a mess of nerves. He sat there feeling as though he were perched on needles, and at one point he moved around and swept his hand across the seat — and his face changed almost imperceptibly.

There was something under the cushion.

He fished it out. An envelope. Unmarked, spotlessly clean.

Looking at it, Xu Ji felt a sudden roar in his head. He had ridden this same carriage to court that morning and home again afterward, and never noticed anything under the cushion. He couldn’t say why, but looking at that blank envelope, he had the uncanny impression that he could see bloodstains on it.

His hands trembling, he drew out the pages inside, and almost shut his eyes before he could make himself read.

Three pages. Quite a few words.

*Chancellor, when you found this letter — did your heart sink?*

From the very first line, Xu Ji could feel Zangjie’s contempt, deep and crushing.

*If nothing has gone wrong, the greenwood brigands you brought back from Shu are likely already discovered.*

*I had them sheltering in a cellar. Any investigator worth their salt should not find them too hard to locate.*

*Once the Court of Justice arrests them, Chancellor, you should understand — your crime of treason is as good as confirmed.*

*If you do not wish to be executed today, or hauled into a prison cell for questioning, you had better think fast. Do whatever you can to stop the Court of Justice from bringing those men into Chang’an.*

*But you are already pressed for time, are you not? You still have a false version of me to bring before the Emperor. Whatever will you do, Chancellor? I confess I worry on your behalf.*

*Of course, I know you have other assets you have not yet revealed. In the years you governed Jizhou as Military Governor, you must have cultivated no small number of assassins. Now is the time to use them.*

*If I were you, I would stop reading here and send word at once, rather than waste time finishing this letter. But I know you are a suspicious man — even if I tell you the rest is useless, you will read it anyway.*

The taunts gave way, on the last two pages, to a detailed account of the reasoning behind Xu Ji’s treason.

There was no way Xu Ji could keep this letter. He read it through, then tore it to shreds with shaking hands. Still not satisfied, he stuffed the fragments into his mouth and chewed and swallowed them whole.

“Stop the carriage!”

He shouted the order through the curtain.

—