Desert Perimeter

"Escort the convoy and evacuate citizens."

That pretext had held for seven days.

May 11, C.E. 71. North Africa, 160 kilometers beyond the Tunisia-Libya border.

Han Zheng looked out from the cockpit of the upgraded Black Iron unit. The panoramic screen showed an endless brownish-yellow plain of gravel, with the ground temperature at fifty-three degrees Celsius. Cold air blew against his back from the ventilation ports in the seat, but everything beneath the collar of his pilot suit was already soaked through.

Tian Mu's voice came over the comms, muffled as though he were speaking from inside a steamer.

"Brother Han, Unit Two's right knee joint is showing a temperature warning—eighty-seven degrees. What's the normal upper limit?"

"Sixty-five."

"Then I'm twenty-two degrees over."

"Try shortening your stride by twenty percent and reduce the frequency of joint flexion."

Tian Mu fell silent for several seconds. Then came the sound of sand crunching beneath the unit's feet as he adjusted its gait.

"It's down to seventy-nine, a little lower. But walking like this feels like wading through water. My speed's dropped by a third."

Liu An from Unit Three cut in, his throat obviously parched.

"Captain Han, Unit Three's Bombard Round belt preheating indicator has already turned yellow. We need to confirm the thermal stability of the ammunition propellant in this high-temperature environment."

Han Zheng stopped his unit and brought up Jiachen's diagnostic interface. The ammunition belt temperature was forty-one degrees, still nine degrees below the propellant's sensitive range, but the trend line kept climbing.

"Deputy Officer Sheng, did you receive the joint and ammunition-belt data?"

Sheng Lan's voice came from the communications vehicle in the rear escort convoy, accompanied by the hum of generators.

"Received. The joint heat dissipation issue is more serious than estimated. The desert's radiant heat wasn't sufficiently sampled in the SEED Framework's climate simulations. Where's Professor Xu?"

From the communications terminal at the 811 Institute, eight thousand kilometers away, Xu Yanqiu's voice burst out.

"Tell them to remove the auxiliary cooling plate on the outside of the right knee joint."

Tian Mu's eyes widened in the cockpit.

"Remove it? Professor Xu, that plate is part of the bulletproof structure."

"Bulletproof my ass. Is anyone shooting at you right now? There's an insulating gasket between the auxiliary cooling plate and the main joint casing. In high temperatures, that gasket turns into an insulation layer instead. Remove the auxiliary plate so air can blow directly onto the joint casing, and the temperature will drop by fifteen to twenty degrees."

Han Zheng glanced out at the desert.

"Professor Xu, is this a temporary solution or a design flaw?"

The comm channel fell silent for three seconds. Xu Yanqiu's voice dropped half a beat.

"A design flaw. The joint cooling module was designed for temperate-climate operating conditions. We never accounted for extreme environments above fifty degrees. We'll modify it after you return."

Sheng Lan added a note to her memo in the communications vehicle, the handwriting slanting at one corner from the vehicle's jolting.

"Professor Xu, what about the ammunition-belt temperature?"

"The propellant's heat-sensitive threshold is fifty degrees. You're at forty-one now, so you still have a nine-degree window. But after two in the afternoon, that window will shrink to less than five degrees. Have the pilots complete any live-fire tests before noon. In the afternoon, rely on the ammunition sunshades to endure it. Once night falls, the temperature will naturally drop."

Sheng Lan slipped her pen into her pocket.

"Han Zheng, adjust today's route plan. The escort convoy will stop where it is. The three Black Iron units will advance to the coordinates for cooling tests and high-temperature firing data collection with the Bombard Guns, then return before two in the afternoon."

"Understood. Tian Mu, Liu An, remove the auxiliary cooling plates first. The tool kits are in the external storage compartments on your left legs."

Seen through the observation camera atop the communications vehicle, the three Black Iron units squatting in the sand and removing armor plates looked like three gray giants crouched in the Gobi, repairing tractors.

Han Zheng took seven minutes to remove his own plate. Just as he was about to stand, a line of text suddenly appeared on Jiachen's tactical screen.

Bearing 217 degrees. Distance: 4,600 meters. Detected four moving heat sources. Speed: 35 kilometers per hour. Carrying metallic objects.

Han Zheng pulled his hand back from the tool kit and gripped the control stick.

"Deputy Officer Sheng, we have a situation here. Jiachen detected four moving heat sources to the southwest."

Sheng Lan's voice immediately tightened.

"ZAFT?"

"Uncertain. They're moving too slowly—not Mobile Suits. Possibly armed vehicles."

Ye Qingluan's voice came from the communications vehicle. She had arrived at the convoy through the intelligence channel only twenty minutes earlier.

"Han Zheng, don't fire."

"Why?"

"Desert Tiger's ZAFT frontline forces are sixty kilometers east of here. They wouldn't appear in this direction using armed vehicles. Those four moving heat sources are most likely reconnaissance vehicles from a local resistance group."

Tian Mu's voice came from Unit Two, his tone tightening.

"Resistance groups have anti-armor rockets too, Team Leader Ye."

Before he finished speaking, an object trailing white smoke flew out from behind a dune and slammed into the sand fifteen meters ahead of Black Iron Unit One's right side. The orange-red explosion threw up a wall of sand, while stone fragments and shrapnel clanged against the Ceramic Steel leg armor.

Tian Mu's comms exploded.

"Fuck, they fired at us!"

"Do not return fire!" Han Zheng shoved the control stick forward, and Black Iron Unit One took a step. Its nineteen-meter-tall dark-gray body positioned itself in front of the escort convoy.

A second rocket followed immediately, striking the Ceramic Steel mounting plate on Unit One's left arm. The warhead exploded, scattering fire across the gray armor and leaving a ring of black scorch marks. The mounting plate did not budge.

On Jiachen's tactical screen, the positions of the four heat sources had already been locked. Ballistic backtracking marked the firing coordinates.

Han Zheng lowered the muzzle of the Bombard Gun, aimed at the air thirty meters above the firing point, and pulled the trigger.

A drill round left the barrel, its rocket boost exploding into a blinding orange fireball in midair. The shockwave rolled over the dunes with sand and dust, shaking all the loose sand off the hoods of the armed vehicles across from them.

The comm channel went quiet.

Han Zheng raised the gun back to its standby position and remained still in the desert.

Thirty seconds later, Ye Qingluan's comms came alive through a contact frequency reserved by the East Asian Intelligence Bureau.

A hoarse male voice on the other end spoke a sentence in Arabic. The translation software lagged half a beat before catching up.

"You aren't the United Army?"

Ye Qingluan's voice was flat and utterly cold.

"No. We are an East Asian Republic convoy escorting merchants and evacuating citizens."

The channel fell silent for five seconds.

"East Asia?"

Another five seconds passed.

"That iron coffin belongs to you?"

Han Zheng heard the term in the cockpit, and the corner of his mouth twitched.

Ye Qingluan did not respond to that description. She only said one thing.

"Put away the rockets. Let's talk."

Several low voices discussing something came from the other side of the channel, mingled with the sputtering idle of engines.

The hoarse voice returned.

"We can talk. But there's a United Army ship eighteen kilometers behind you in that direction. If you're with them, there's nothing to discuss."

Sheng Lan's hand paused over her memo in the communications vehicle.

In the lower-right corner of Han Zheng's panoramic screen, Jiachen quietly refreshed a line of data.

Bearing 039 degrees. Distance: 17.6 kilometers. Detected a large metallic structural heat source. Match rate with known warship signature database: 92 percent.

Match result: Archangel.