I started with a ship full of max-level veterans, and I'm just a complete noob.

A dozen seconds later, the magnetron inside the lead box finished preheating, and the dark red filament cast a blood-red glow on the ceramic base.

The coaxial feeder connecting the underground pipelines vibrated and hummed through the lead walls, drowning out the footsteps in the old laboratory.

The technical supervisor stuffed the metal cylinder into the canvas bag, signaling the two operators to stop.

The twelve sets of detonators along the wall have been integrated into the same detonation plate, with the lines extending to the main entrance and the side tunnels on both sides.

"The rendezvous coordinates have been received. The passage will be closed in ten minutes. Anyone who hasn't arrived yet, stay up there and block them."

An operator looked at the still-operating centimeter-wave radiator, his hand still holding the documents.

"The 7 MHz frequency has been exposed. If we turn this machine on again, the base will discover a new frequency band."

"It's too late to detect it; they'll just treat it as residual interference."

The technical supervisor opened the detonator's protective cover and inserted the key into the lock.

As the magnetron power increases, the pointer on the dial gradually approaches the green mark.

At the same moment, 15 kilometers away on the ground, two jeeps had already bypassed the road on the east side of the base. Director Wang's guard team went straight into the barren rocky beach, the sand kicked up by the wheels rolling backward along the ground.

Another convoy turned from the hill into Mine No. 04. A light armored vehicle towed an equipment trailer, with trucks behind carrying the Yuanlei-1, pulse modulator, and diesel generator. The tracks and tires continuously rolled over the gravel.

Jiang Ming sat in the rear compartment of the armored vehicle, with a military map of the mining area spread out on his lap. The shockproof box of Yuanlei No. 1 was leaning against Lao Sun. Every time the vehicle drove over a stone pit, Lao Sun would brace the box with his shoulder.

"Tighten the tow rope one more loop. We're heading into a ditch. If the box gets damaged, we won't even have a second chance to set it up."

After inspecting the copper buckles, Lao Sun dragged the toolbox to his feet, arranged the socket, locking pin, and protractor in the order of use, and waited for the vehicle to stop so he could go down and set it up.

Fang Xudong was guarding the mobile field strength meter. The broadband interference on the meter had dropped to a low level. After the seven-megahertz communication ended, only a few segments of residual waves remained in the mine that could not form a code.

"They have stopped sending messages. The technical supervisors have probably already obtained the coordinates and are preparing to withdraw through the southeast passage."

Lu Qinghe didn't respond to that sentence. She turned the sweep frequency knob of the mobile direction finding device past the shortwave zone and continued to push towards higher frequency bands. Between the regular and monotonous background noise in the headphones, there were always short tapping sounds.

That energy appears only for a very short time each time, and the repetition intervals are not fixed, but it never leaves the same frequency band.

As the armored vehicle drove over a slope, the equipment frame rattled from the vibrations. Lu Qinghe held the panel steady, narrowed the scanning bandwidth, and then overlaid the last three pulse records onto the transparent film.

"Jiang Ming, take a look at this."

She handed over the frequency spectrum diagram. The three thin peaks on the right side of the paper almost overlapped the same vertical line, indicating a frequency far higher than that of the existing communication and jamming equipment in the mine.

Jiang Ming marked the pulse intervals with a pencil and placed the parameter table of the previously captured equipment next to it. There was a large blank space between the upper limit of the Soviet-made receiver and these three thin peaks.

"The frequency does not drift, and the pulse width does not carry Morse code; it does not transmit messages."

After Fang Xudong moved the near-field strength meter and recalibrated the range, the meter head still only moved in a fixed position.

"The three power amplifiers in the mine have lost their lockout, and the standby local oscillator is operating in the shortwave band. Where did they get the centimeter-wave equipment?"

"It's not the original system."

Jiang Ming flipped the blueprint to the back and drew a magnetron and two coaxial lines, connecting one end to the metal pipe network inside the mine.

"These parameters have exceeded the usual upper limit of existing Soviet-made equipment. Something capable of reaching this frequency should not be found in an old mine."

Lu Qinghe took off her headphones and wrote the pulse repetition period she had just recorded on the side of the graph.

"Each time it jumps, it coincides with the load change of the underground power grid. After starting, it does not call a sign or perform frequency sweeping."

"Because it doesn't need a receiver."

Jiang Ming moved his pencil outward along the tunnel markings on the military map, connecting the main tunnel entrance, ventilation shaft, transport shaft, and old water pipeline into an irregular grid.

Steel pipes, tracks, and abandoned feeders left over from early mining operations penetrate the rock strata. If someone measures their length beforehand and then couples centimeter-wave energy into them, these metal pipes can act as antennas and resonant branches.

The energy does not need to cover the entire mining area; as long as a high field strength is formed at a predetermined node, it can break down the sensitive device connected to the detonator.

Fang Xudong saw the connection method in the picture and reached out to press down on the corner of the paper that had been lifted up by the vehicle.

"You mean, they're planning to use wireless ignition?"

"The radiator is responsible for sending out the detonation pulse, the underground pipeline is responsible for guiding the energy to the vicinity of the detonator, the main entrance is just a decoy, and the real detonation point is hidden in the rock strata."

Two short blasts came from the front of the armored vehicle, indicating that the reconnaissance vehicle was approaching the entrance to the North Gully, and the advance troops of the First Battalion were waiting for the final order to advance.

Jiang Ming raised his hand and knocked on the cockpit partition.

"Stop the car and give me the coordinates of the front line."

The driver applied the brakes, and the armored vehicle came to a stop behind the scree slope. The radio operator wrote the latest positions of the first and second battalions on the edge of the military map.

The first company of Beigou had already crossed the second fork in the road and was less than 600 meters from the main tunnel entrance. The vanguard platoon of the second battalion had also entered the abandoned mine track on the west side. The two units were just outside the coverage area of ​​the underground metal pipeline network.

If they advance another 300 meters, they will simultaneously step into the detonation zone surrounded by multiple resonant branches.

Jiang Ming took out a clean sheet of white paper and, based on the elevation, pipe diameter, and branch length in the old mine map, continuously drew the standing wave distribution after the underground coaxial feeder and steel pipe were coupled.

The carriage was still swaying from the engine's aftershocks. His pen tip moved forward along the paper without looking back to revise any section. Several electrical current points quickly landed on the gravel platform outside the main tunnel entrance and the bend in the western mine track.

"Notify the First and Second Battalions to halt their advance, and all personnel to retreat beyond this line. No vehicles should cross the abandoned tracks."

The communications soldier looked at the red line on the paper that ran across the front lines of the two units, but did not send a message immediately.

"Captain Jiang, we're only a few hundred meters from the cave entrance. The assault company has already deployed. Retreating any further will give up the high ground."

"They moved forward, and there was no need to send anyone out to guard the mine. They could just press a switch to bury both teams in the tunnel."

Jiang Ming grabbed the microphone and transmitted the halt order directly to the command network. The response from the assault company commander came immediately from the front line of Beigou.

"We found no fuses or mine markers, and the engineers have already checked the main road."

"The fuse is buried next to the underground pipeline, which the engineers can't see right now. Everyone has retreated back to the red line and is waiting for the artillery to handle the ventilation shaft."

The artillery battalion commander's voice quickly entered the channel, with the sounds of gun breech opening and closing and rangefinders reporting numbers coming from the background.

"Why target the ventilation shaft? The main entrance is the enemy's firing point. We don't have enough shells left, less than two rounds; we can't just randomly fire at a chimney."

Jiang Ming unfolded the underground standing wave map. The ventilation shaft was located on a high slope on the north side of the mine, more than 700 meters away from the main entrance. From the perspective of conventional attack, there was indeed no shooting value there.

"The ventilation shaft is connected to the generator room. The centimeter-wave radiator and the detonator are both powered by this line. As long as the power supply bus is cut off, the underground minefield will not be able to be ignited."

"How do you know the generator room is below the ventilation shaft if you haven't even gone inside?"

The artillery battalion commander remained silent, and the forward troops stayed put. No one wanted to change the firepower plan based on a temporary sketch just as the encirclement was about to be completed.

Jiang Ming looked at the high-frequency pulses recorded by Lu Qinghe and wrote down the previous rotation pattern of the three generators in the mine on the white paper.

"Give me ten minutes, and I'll hand over the evidence to you."

"Ten minutes. If there's no concrete evidence by then, I'll proceed with the plan to bomb the main entrance. If the front line doesn't move, the people inside the mine might escape through the southeast branch tunnel."

The walkie-talkie fell silent again. The communications soldier looked up at his watch; the hands had already passed 12:30.

"Drive the car up the side slope of the rocky gully, the antenna needs to cross the rocky ridge."

The driver stepped on the accelerator, and the armored vehicle slowly climbed up the gravel slope.

As the mobile direction-finding antenna was raised along with the vehicle, the low outline of the north slope ventilation shaft was revealed between the two rock ridges.

There were no lights at the wellhead, only a wisp of pale gray heat rising out along the protective netting, constantly being pushed against the slope by the cold wind after the sandstorm receded.

Jiang Ming placed the pencil at the intersection of the ventilation shaft and the underground busbar.

The temperature, spectrum, and power ripple there will determine whether the two assault teams can enter the mine alive.