The boomstick exchange at four hundred paces was the exchange that both sides had been marching toward, the range where the dwarven-forged weapons on both sides reached the accuracy that made each shot a likely hit rather than a probable miss.

Forty-two thousand Threian boomsticks fired in the rolling volley that the Threian military’s training prescribed. The volley was the volley that the Threian army had been delivering since the dwarven trade had first provided the weapons, the coordinated fire that produced a wall of lead that crossed the four-hundred-pace distance in the time that the balls’ velocity determined and struck the barbarian formation with the density that forty-two thousand weapons produced.

The barbarian formation absorbed the volley the way a rock face absorbed rain. Warriors in dwarven armor staggered, stumbled, some fell. The dwarven iron that the barbarians wore was the same dwarven iron that the Threian army wore, and the dwarven boomstick balls that the Threian army fired were the same caliber as the balls the barbarians fired, which meant the balls struck armor that had been designed to resist those specific balls at those specific velocities. Some balls penetrated. Some did not. The result was the result that identical weapons and identical armor produced: casualties proportional to the volume of fire rather than the weapons’ superiority, because there was no weapons superiority when both sides fought with the same weapons.

The barbarian return volley struck the Threian formation at the same range. Seventeen thousand boomsticks firing in the staggered volleys that the barbarian training produced, less disciplined than the Threian volleys but compensated by the specific advantage that unlimited ammunition provided: the barbarians could fire faster because the barbarians did not need to conserve. Every ball fired was replaced by the next supply wagon. Every charge consumed was replenished by the dwarven powder that the mountain routes delivered.

A Threian sergeant in the king’s center took a ball in his left pauldron. The dwarven armor deflected the ball downward into the joint where the pauldron met the breastplate, the ball’s altered trajectory finding the gap that the deflection created and entering the shoulder at the angle that the gap’s geometry permitted. The ball lodged in the muscle beneath the shoulder blade. The sergeant’s left arm went numb. He shifted his boomstick to his right hand, braced it against his hip, and fired one-handed.

"Reload!" His loader, a sixteen-year-old conscript whose hands shook with the specific tremor that first-engagement adrenaline produced, packed the next charge with the speed that three weeks of drill had provided. The charge went in. The wadding followed. The ball seated. The sergeant fired.

* * * * *

The magical battle escalated at the three-hundred-pace mark.

The two Seventh Circle shamans entered the field.

They had been standing on the ridgeline’s highest point since the battle’s start, their bodies painted in the ritual markings that Seventh Circle practice required, their chanting a deep harmonic that the lesser shamans’ chanting wove around like threads around a cord. When the Threian advance reached three hundred paces, the two shamans raised their staffs simultaneously and the sky split.

Not figuratively. The air above the battlefield cracked along a line that ran from the barbarian ridgeline to the center of the Threian formation, the crack visible as a distortion in the light that the atmosphere produced, the crack the specific manifestation of Seventh Circle atmospheric manipulation applied to the thermal layers that the air contained.

The crack produced a downdraft. Not wind. A column of compressed air that descended on the Threian formation’s center with the weight that atmosphere possessed when atmosphere was compressed by Seventh Circle shamanic energy into a density that natural conditions did not produce. Soldiers in the downdraft’s path were driven to their knees by the air pressure. Shields were pressed flat against bodies. Boomsticks were forced from grips that could not maintain their hold against the pressure that the compressed air column produced.

The downdraft lasted eight seconds. Eight seconds during which the Threian center’s three thousand soldiers were pinned by atmosphere, unable to advance, unable to fire, unable to do anything except endure the pressure that the Seventh Circle shamans’ combined power produced. 𝚏𝐫𝚎𝗲𝕨𝐞𝐛𝕟𝚘𝐯𝚎𝗹.𝕔𝐨𝗺

The barbarian boomstick fire concentrated on the pinned center. Three thousand soldiers pinned in place by atmospheric magic while seventeen thousand boomsticks fired into them for eight seconds. The mathematics of the eight seconds were the mathematics that concentrated fire against stationary targets produced: the casualties were catastrophic.

"YOUR MAJESTY!" Fairfax’s shout was the shout of a Fifth Realm practitioner whose senses detected the Seventh Circle’s power signature and whose professional assessment of the signature’s source produced the specific urgency that the assessment demanded. "The Seventh Circle shamans are in the field! The atmospheric manipulation is Seventh Circle! We need the Sixth Circle response NOW!"

King Aldric stepped forward.

The Sixth Realm’s power blazed from the king’s body in the golden aura that the Realm’s activation produced, the specific manifestation of a monarch whose Realm’s power was the Realm’s response to the threat that the monarch’s kingdom faced. The golden aura expanded outward from the king’s position, pushing against the atmospheric downdraft, the Sixth Realm’s energy contesting the Seventh Circle’s atmospheric manipulation with the specific resistance that one Realm below the threat’s source provided.

The downdraft wavered. The Sixth Realm’s power was less than the Seventh Circle’s power, the exponential gap between Circles manifesting as the difference between the downdraft’s full compression and the downdraft’s contested compression. The soldiers in the center were no longer pinned. They were pressed. The difference between pinned and pressed was the difference between immobility and difficult movement, and difficult movement was sufficient for soldiers whose training had been built on the principle that movement, however difficult, was preferable to stillness under fire.

The center moved. The advance resumed. The boomstick fire continued from both sides. And above the battlefield, the Sixth Realm’s golden aura and the Seventh Circle’s atmospheric crack contested the sky with the specific visual that magical combat at the highest levels produced: light against pressure, the kingdom’s strongest power against the barbarians’ strongest magic, neither sufficient to defeat the other and both sufficient to prevent the other from being decisive.

The boomstick exchange’s arithmetic was the arithmetic that defined the entire engagement’s sustainability. The Threian force’s combined boomstick ammunition, Aldrath’s seventy-three percent plus the king’s twenty-six percent, averaged to approximately fifty-four percent across the combined force. The barbarians’ ammunition was unlimited. The exchange rate at four hundred paces was approximately one casualty per eight balls fired on both sides, the rate determined by the armor’s protection and the weapons’ accuracy at the range. The Threians fired more balls per volley because they had more boomsticks. The barbarians fired fewer balls per volley but could fire indefinitely.

The mathematics of the exchange said that the Threian force’s ammunition would sustain approximately four hours of continuous boomstick engagement at the current rate of fire. After four hours, the boomstick fire would diminish as ammunition conservation measures reduced the rate of fire. After six hours, the boomstick fire would be sporadic. After eight hours, the boomsticks would be empty and the Threian force would fight with steel.

The barbarians did not have an eight-hour limit. The barbarians had no limit. The dwarven wagons that sustained the barbarian ammunition supply were parked behind the ridgeline with the fresh stock that the mountain trade routes had delivered that morning, the stock that would be replenished by the wagons that were already en route from the Iron Hills.