Batu made the route every morning before the horse lines had run their first allocation. He started at the south gate and went east, following the perimeter at two hundred and fifty meters from the wall, watching the city’s condition from what the south and east walls showed him.

The ride took about an hour, and he hadn’t skipped it once.

The south gate was the most changed. The original timber above it had burned as the fire projectors had hit it repeatedly, and whatever the garrison tried to patch with, the projectors found that too.

What the gate looked like now was a section of wall where the palisade posts were shorter and lighter-colored than the logs on each side, new timber set over burned timber, and even some of those patches showed their own char now.

Chaidu came alongside him near the eastern section. "Report about the north tower,"

He read it aloud. "When we started it had eight men on it most of the time. It’s got four now, maybe five."

Batu kept his eyes on the wall. "Are they the same men or under a rotation?"

"Different coats every time we’ve watched, they’re rotating."

Batu didn’t answer.

The garrison was short of men. Men who’d been on the walkways for days had died there, either from the newly built trebuchets, from the projectors, and from the cold nights.

Even then the city still had men on those walkways.

The trebuchets were behind the earthwork berm Zhao had built in the first week, positioned to throw over the south wall. Two of them, timber-frame machines built from the local forest timber by Zhao’s eleven men. Each had a long arm with a leather sling at the far end.

The crew was twelve riders on the short end. On Zhao’s count they all pulled together, the arm swung up, the sling released, and the stone went in an arc over the wall and into the city’s interior.

From more than two hundred meters out, the impact sound reached Batu a moment after he saw the smoke. A crash, something under collapse, and then the smoke beginning to rise from wherever the stone had landed.

Zhao was at the near trebuchet when Batu reached that part of his route, watching the smoke rising inside the city from the last throw. He didn’t look at Batu.

"How’s the siege equipment?" Batu said.

"Under good condition, of course. We can shoot eight times an hour between both machines,"

Zhao looked proudly at their work. "As requested, we are also shooting at them fire pots with enough animal fat to set a building ablaze."

He kept his eyes on the smoke. "They’ve been dealing with the fires every day now."

Batu watched the grey column rise.

"How far in can you reach?" he said.

"The center of the city at best. I can’t see what we’re hitting, but there’s something in there."

He turned back to his crew. They were already loading the next stone.

Fang was crouched at the first fire projector’s reservoir when Batu reached him. He looked up when Batu stopped, and his expression said something before he said anything.

"There’s a problem, we’re using more compound per day than the Sarai tests expected."

Batu looked at the reservoir. It was indeed lower than it should have been.

"At Sarai we tested it in short sessions."

Fang continued. "Out here we run it for hours at a stretch, and the heat changes how the compound moves through the nozzle. It gets thicker, so it doesn’t flow the same and I’m pushing it harder to get the same effect. That uses more."

"How many days at the current rate before we’re below enough for the assault?" Batu said.

"Three," Fang said. "Maybe four, I’ve been counting every refill."

He paused, then added, "I’ve got enough for the assault if we cut down on the usage."

"I need the projector to fire at least enough to prevent them from repairing the gate."

Fang had already thought about it. "We’ll do two-thirds them. It keeps the gate under pressure, not as often, but often enough that they can’t repair freely."

Batu nodded. "Then we use two-thirds, starting now."

Fang nodded and reached for the reservoir fitting. "I’ll work out the refill schedule, there’ll be enough for the main assault."

Batu continued his inspection through the western section.

The garrison had gone through the gate two nights ago there, a small door set low in the palisade base, the kind used for supply in quieter times. Fifteen riders, maybe twenty, moving in the dark for the nearest weak point in the encirclement.

They’d reached the formation and killed eleven riders before they were driven them back. Twelve made it back through the gate, the rest were on the ground outside the wall.

It hadn’t created a breach and it hadn’t changed anything about the siege, but a garrison that was still willing to bleed for a night raid after daily bombardment still had fighting force left in it.

Dorbei’s mingans came in from the east in the early afternoon. Five thousand riders, the column visible from its dust before the individual horses appeared through it.

The eastern section spread to accommodate them, both the arriving riders and the stationed ones making room without requiring direction. It was the kind of adjustment that large cavalry forces did by shared instinct when they’d both been doing this kind of work long enough.

Dorbei came to the column’s front when it had settled. He looked at the city’s eastern wall and then at Batu. "I left five mingans to clean up the forest. Whatever’s left in those trees isn’t a formed force anymore, just cowardly men hiding."

Batu nodded, and let Dorbei familiarize himself with the siege progress.

He looked at the patched palisade above the south gate, at the lighter timber over the darker. There was no need to comment on it, and he simply turned his horse back toward his formation.

The relay rider from Orda came before the afternoon was gone, riding hard enough that the horse was breathing through its mouth when it stopped. The message was brief, how every Kama river route was sealed, that Džuketau was destroyed, and the White Horde was marching south with an estimated arrival in two to three days.

Batu knew the time wasn’t coincidence, Orda knew exactly when the siege would need his force.

He dismissed the rider and turned north, and the second relay rider found him before he’d covered a hundred meters.

This one was from Toqa-Timur at the Bilyar siege. The perimeter was set up, but the garrison was larger than the plan had accounted for.

His riders had been watching the walkways and putting the count against what they’d been told to expect, and the number didn’t match.

Toqa-Timur wrote some of what had gotten out of Suvar in the winter had ridden north to Bilyar, men who’d been through a Mongol assault once and knew how the assault riders fought after the gate fell.

The siege was ongoing, no breakthrough yet.

Batu thought about the men who had gotten out of Suvar alive. They’d arrived at Bilyar with something Bilyar’s garrison hadn’t had before them, a picture of the army coming for them from the inside of an assault they’d survived.

"Tell him to keep the pressure on the walls," Batu said to the rider.

The rider acknowledged it and went.

Batu held his position on Daichin and looked at the city. The trebuchet crews were on the next throw, the arm swinging up, the stone going over the wall. The impact sound came back a breath later, something heavy destroying something weaker.

The garrison archers on the walkways watched the encirclement and did not shoot. The range was too long and they had been counting their arrows for days and knew it.

The north wall of the city was open ground, empty from the wall out to the horizon, flat land up to where the Volga bent north. In two or three days that ground would fill with Orda’s White Horde and there would be no side of this city left unwatched.

After that the assault.