The southwest marsh lay two miles below Harth, where the river flattened into a wide, braided delta of gray water, black willows, and rotting reed beds that smelled of stagnant ditch water and sulphur.
Jon walked along the muddy towpath, his heavy cowhide boots sinking two inches into the sodden clay with every stride. The drizzle had ceased, but the low sky remained the color of an unwashed tin trencher, pressing down upon the valley until the chalk ridges to the east looked like smudged charcoal lines. Over his shoulder he carried an ash-wood measuring rod, notched in six-inch spans, and at his belt hung a tin collecting flask stoppered with grease-soaked linen.
Beside him walked Old Darrow, a retired river barge-hauler who had spent forty years towing timber rafts through the shallows. Darrow was sixty-four, stooped like a bent willow, with a crippled right hip that made him drag his boot with a wet, sucking scrape through the mud.
“You’re wasting good shoe leather, Master Hale,” Darrow rasped, spitting into the ditch weed. “There’s nothing at Low Sike except mud and leeches. The gravel shelf hasn’t seen a market cart since the Duke built the high toll bridge thirty years ago.”
“Cattle can still cross it,” Jon said, keeping his eyes on the gray reeds ahead.
“Cattle can cross it if you don’t mind losing two heifers to the silt holes,” Darrow muttered. “The bottom is soft. A beast takes three steps into the shallows, the mud takes its knees, and the river does the rest. Why does an innkeeper care about a marsh ford when the King’s hero is sitting in his taproom eating mutton stew?”
“A man who doesn’t watch his back ditches finds water in his kitchen,” Jon answered, stopping where the towpath crumbled into an expanse of dark, standing water.
This was Low Sike.
Here, the main river channel split around a low, tear-shaped island of stunted alders, creating a shallow reach eighty paces wide. The water was barely knee-deep over the gravel bar, but the current was sluggish, trapped by the autumn reed choked shallows. The surface had an oily, iridescent sheen, scummed with pale yellow foam that collected around the alder roots like curdled milk.
Jon stepped off the towpath, wading into the cold shallows.
The river water soaked through his leather boots within five strides, chilling his ankles with the biting cold of Flood Month runoff. He planted his ash rod into the silt, watching the dark muck swirl around the wood.
Twelve inches of soft silt. Beneath the silt, a firm, packed bed of river gravel three feet wide, curving across the reach in an irregular S-shaped traverse that connected the northern bank to the low southern meadows.
A ford. An unmapped, unfortified, and completely undefended crossing that bypassed the north palisade, bypassed the bridgehead, and led straight into the rear lanes behind Harth’s church terrace.
Jon knelt upon an exposed willow root, dipping his bare fingers into the cold water.
HONEST MEASURE.
The skill probed the chemical and biological composition of the pool. Immediately, the diagnostic pulse picked up a sharp, oily frequency that did not belong to wild river fish or common mud pike.
The stench hit his nostrils a breath later: an iron-heavy, rank odor that smelled like slaughterhouse runoff mixed with stagnant brine.
Beneath the surface of the silt, three paces out into the current, the dark mud was moving.
A series of undulating trenches, six inches wide and carved like ribbons through the submerged weeds, snaked across the gravel bar. As Jon watched, a long, sinuous shadow, pale belly flashing silver in the murk, broke the surface of the mud. It was an eel, thick as a man’s bicep and five feet long, its skin covered in mottled gray plates that resembled boiled river slate. Along its blunt snout ran four fleshy, whisker-like barbs, vibrating with acoustic sensitivity, homing in on the warm pressure of Jon’s hand in the water.
A blood-eel.
Jon pulled his hand back instantly, his fingers dripping with foul, brackish slime.
The creature’s snout broke the water with a soft, sucking hiss. Its jaws opened, revealing four concentric rows of needle-sharp, triangular teeth made of blackened bone, snapping shut with the sharp, hollow crack of an iron spring trap. Finding only cold air where the warmth had been, the beast lashed its tail, churning the black silt into an opaque cloud before burrowing back into the mud.
Darrow stood on the bank, his hand gripping an alder branch, his face pale beneath his white stubble.
“Gods above,” the old hauler whispered, crossing himself with trembling fingers. “That’s an Ash Host beast. I saw them in the border war twenty years ago. The northern marsh-sappers breed them in horse blood and brine. They set them loose in the fords to break infantry lines.”
“They track warm blood,” Jon said, rising from the root and wiping his hands with a handful of dry reed stalks. “They lie dormant in the cold silt until an infantry company or a horse column wades into the water. Then the heat wakes them. They go for the tendons behind the knee. In five minutes, forty men are down in the mud with their arteries torn open, screaming while the river turns black.”
In his third life, Jon had watched Captain Dain lead forty town militia into this exact ford to intercept what the captain believed was a small band of enemy outriders. The militia had never reached the alder island. The blood-eels had shredded their legs within ten paces of the bank, dragging men under while northern archers stood on the southern berm and shot them like trapped hogs.
The memory burned in Jon’s chest with the bitter, coppery taste of gall.
“They’re already here,” Darrow said, his voice shaking with terror. “The Host vanguard hasn’t even crossed the ridge, and their beasts are already seeded in the flume.”
“A scout on a fast mare brought three tubs of young eels down the valley two nights ago,” Jon said, analyzing the tracks in the mud. “They tipped them into the shallows and drove iron stakes into the riverbed to keep them from drifting downstream. When Marshal Ors orders his marsh cavalry across on Friday morning, the eels will be starved and hunting.”
“We must tell Captain Dain,” Darrow insisted, turning his crippled hip toward the towpath. “The town watch must bring sulfur and burn the reed beds!”
“If Dain brings forty guardsmen down here with torches and pitch, Cael will order them back to the causeway within an hour,” Jon said, his voice cutting through the old man’s panic like an iron wedge. “Cael wants this ford open.”
Darrow stopped on the path, his jaw dropping in bewildered disbelief.
“He wants it open?” the hauler rasped. “To let northern cavalry butcher our folk in the churchyard?”
“To keep the main assault predictable,” Jon answered, his hand resting on the ash rod. “Cael’s geometry requires the Host to commit its heavy infantry to Bridge Street. If he blocks this ford with timber and guards, Marshal Ors will see the barricades, realize the flank is sealed, and redirect his heavy siege engines against the western wall. Cael wants the Host to believe this crossing is their secret route. He is willing to sacrifice forty militia at the water’s edge to keep the enemy’s timetable running on his terms.”
Darrow stared at him. The old man’s eyes, clouded with age and river rheum, filled with a sudden, devastating comprehension.
“He’s using us for bait,” Darrow whispered.
“He’s using the arithmetic he was given,” Jon said. He reached down, unstoppered his tin collecting flask, and scooped up four ounces of the foul, eel-fouled river water from the edge of the silt. He sealed the flask, wiped the rim, and tucked it into his coat pocket.
He looked across the eighty paces of shallow water toward the far bank.
The blood-eels were resilient, armored against cold iron and bred to ignore fire, but they had one biological vulnerability that Jon’s Keeper trade understood better than any royal ordnance general. They were fresh-water marsh predators, native to the peat bogs of the high north. Their sensory barbs relied upon delicate, unshielded mucosal membranes to detect heat and mineral currents in the water.
If the salinity of the water shifted suddenly—if the brackish silt was saturated with concentrated mineral salt—the caustic brine would blind their sensory barbs within sixty seconds. The beasts would lose their sense of direction, thrash in agony, and turn upon the nearest warm flesh they could find: the horses and riders of the cavalry vanguard driving them through the shallows.
“How much salt is sitting in the municipal warehouse at North Quay, Darrow?” Jon asked, stepping back onto the dry towpath.
The old hauler blinked, his mind struggling to follow the sudden shift from military terror to merchant logistics.
“The salt warehouse?” Darrow repeated, wiping a hand across his wet chin. “Mistress Bessa Karr has seventy cartloads of coarse rock salt sitting under the quay shed. Shipped up from the southern salt pans before the road tolls were raised. She’s been trying to sell it to the pork curers for two months, but nobody has the silver to buy sixty tons of rock.”
“I have the silver,” Jon said.
He looked back at the gray reeds, where the dark trenches in the mud were already filling with river silt, concealing the four rows of needle teeth waiting in the cold shallows.
“Come, Darrow,” Jon said, taking the old hauler by the arm to steady his limp. “We have seventy carts to hire, and an innkeeper’s fortune to spend before the afternoon bell.”