Impenetrable Skin

But Lynn's Super Senses told him that 3.7 centimeters beneath the scar, there was a foreign metallic object about nine millimeters in diameter.

Its vibration frequency was completely different from the surrounding human tissue—it was the faint, high-frequency resonance unique to Vibranium.

"When were you hit?" Lynn asked.

"Two weeks ago," Claire answered for Luke.

She spoke quickly, as if she had prepared the explanation long ago.

"Someone in the Harlem District got their hands on a batch of special bullets. Luke took a hit while stopping a shooting. The bullet pierced his skin—that was the first time he was truly wounded by a bullet."

"But the problem is, his skin heals too fast," Claire's voice carried clear frustration.

"The wound closed before we could even extract the bullet. Now it's sealed inside his body, and the skin on the outside is as hard as—well, nothing can cut it."

"What methods have you tried?"

"Drills. Chainsaws. Even sulfuric acid," Claire listed them in one breath.

"The drill just skidded off without leaving a mark. The chainsaw managed to generate some heat on the surface, but the cutting depth was zero. As for the acid—I used industrial-grade concentrated sulfuric acid and left it on his skin for forty minutes; it only softened the top layer by less than 0.1 millimeters."

"And the acid treatment hurt like hell," Luke added.

His voice was deep and resonant, as if it were rolling out from his chest.

"I'm not afraid of pain, but that kind of pain is pointless. The acid can't get in, and the bullet can't get out."

Lynn did not speak immediately.

He placed his hand over the scar on Luke's abdomen, pressing down gently.

The tactile feedback from his Super Senses penetrated the surface layer—he could feel the structure of Luke's skin.

This was not normal human skin.

A normal person's skin consists of three layers: the epidermis, the dermis, and the subcutaneous tissue.

Luke's skin also had three layers, but the density and hardness of each far exceeded normal values.

The dermis, in particular, contained a protein structure he had never seen before, arranged with extreme density to form a multi-layered, intersecting fiber network.

The deep-scan mode of All-Things Diagnosis provided more precise data—the inherent resonant frequency of this protein network was 39.14 kHz.

Inherent frequency.

Every substance has an inherent frequency.

When an externally applied vibration frequency matches the inherent frequency of a substance, resonance occurs.

In a state of resonance, the internal structure of the material temporarily loosens.

Luke's skin wasn't impenetrable—no one had found the right "key."

"I need an ultrasonic device," Lynn said. "High-frequency. The frequency adjustment precision needs to be at least two decimal places. Military-grade would be best."

Claire raised an eyebrow. "Ultrasound?"

"Yes."

"You're going to use ultrasound to cut his skin?"

"Not cut. Soften."

The three of them looked at him simultaneously.

Although Matt could not see, his face was turned toward Lynn, collecting data on his heartbeat and breathing as he spoke—using it to judge whether he was bluffing.

"Are you sure?" Luke asked.

"I need that device to be certain," Lynn said. "But theoretically, it's feasible. The problem is—you can't buy this level of ultrasonic equipment through normal channels."

He looked toward the door.

Frank had said he would be back late before heading out on "patrol" tonight.

But he had left a contact method—a burner phone used only for receiving text messages.

Lynn sent a message: "Need a military-grade ultrasonic generator, frequency range 30-50kHz, precision 0.01kHz. Within two hours. Can you get it?"

A reply came thirty seconds later: "One hour and forty minutes. Leave it at your back door."

"The equipment is on its way," Lynn told Luke. "Rest for a while. Surgery in two hours."

1:37 AM.

Lynn moved the military equipment case that Frank had left on the back steps into the VIP operating room.

He opened the case.

Inside was a military-grade ultrasonic generator, the USG-M7 series used by the U.S. military medical corps.

The normal price for this thing was probably over thirty thousand dollars; Lynn didn't ask how Frank had managed to get it in an hour and a half.

He only asked one question: "Does it work?"

Frank's text message replied with a single word: "Yes."

Lynn spent forty minutes modifying the instrument.

The mechanical engineering knowledge of Batman within his Super Intelligence played a huge role at this moment—

He recalibrated the circuit parameters of the frequency generation module, increasing the output frequency precision from the kHz level to four decimal places.

Then, he hand-crafted a focusing probe, assembling it from stainless steel tubing in the clinic and a piezoelectric crystal salvaged from an old device.

It was 2:20 AM by the time he finished.

Luke had been waiting in the clinic for nearly three hours.

Claire was keeping him company.

Matt sat in the waiting area outside, leaning against the wall and pretending to rest, but his Super Senses were constantly monitoring the activity inside.

"Ready," Lynn said, pushing open the door to the VIP operating room. "Only you come in; everyone else waits outside."

Claire opened her mouth to say something.

"His surgery doesn't require an assistant," Lynn looked at her, "and you might see things in there that you'd rather not."

That sentence carried a lot of weight.

Claire hesitated, but ultimately did not insist.

Luke walked into the operating room.

His size made the room feel significantly more crowded.

When he lay down on the operating table, the metal frame let out a disgruntled "creak."

"Are you sure this table can hold me?"

"It can. I reinforced it specifically."

Lynn secured the modified ultrasonic probe to an adjustable stand, aiming it at the scarred area on Luke's abdomen.

"You might not have seen what I'm about to do," Lynn said while calibrating the instrument.

"I'm going to use ultrasound to create a localized resonance on the surface of your skin. The resonance will temporarily soften your skin—the window is very short, only about thirty to forty seconds. During that window, I'll cut the skin, find the bullet, and remove it."

Luke stared at the ceiling. "How do you know ultrasound can make my skin soft?"

"Because all matter has an inherent frequency. Even though your skin is hard, it is ultimately composed of protein molecules. Proteins have molecular vibration characteristics; applying a matching frequency can temporarily disrupt the cross-linked structure between the molecules."

"Besides being a doctor, do you also study physics?"

"I'm a fast learner."

Lynn turned on the ultrasonic generator.

A low humming sound filled the operating room.

He began to adjust the frequency.