"It takes more than fifteen years of training to train a bloodhound that can sniff out the traces of the blood, and it also requires a living bloodline to train to." George continued.

"This is not the most troublesome, the vast majority of hunting dogs will hide as far away as possible after smelling the unique smell of the bloodline, out of the characteristics of biological advantage and avoidance, at least a very small number of hunting dogs will track this smell - this kind of hunting dog genetics generally has a certain defect, and it is this 'defect' that causes them to no longer be afraid of the bloodline."

"My father used to have such a hound, but when I was five years old, the old hound was dead...... Luckily, I was able to invent the 'developer', which is an extremely important invention even in the thousand-year-old history of the Hesin family. ”

"Developer? Is it the kind of stuff used for vintage film photographs? Isn't that something that's been around for the last century? Are you embarrassed to say you invented it? Qi Lin said.

"I just borrowed the name, except for the silver halide in the ingredient list, my 'developer' and the developer used to wash the photos are completely different things, and the 'shadow' it can show is the trace of the blood family." George said confidently.

"Okay, I'll trust you for a while, I hope your 'developer' can come in handy......" Qi Lin said as he glanced at George's list again.

Luckily, Vault 209 is at least a medium-sized Vault, and it's well located in the underground Vault network, on a spur line of a major transportation road, and the chemicals are hard to come by, but not completely out of the question.

If this were to be placed in some remote place, I am afraid that even half of the items on the list would not be enough.

……

……

The torture room borrowed by Qi Lin had been turned into a chemical laboratory, and the interrogation table was dragged to the center of the room, filled with glassware containing various chemical reagents, and next to the table, there was a large ceramic crucible, which was filled with all kinds of black and unknown reactants.

At this moment, George was lying on the ground, holding a long-necked flask with an asbestos glove in his left hand, and a flamespray gun in his right hand, carefully heating the mixture in the flask.

"Phew!!"

The long-necked flask suddenly exploded, and George had already taken the first step to pull over a metal plate at his side, quickly protecting his body behind the metal plate.

The shards of glass hit the metal plate with a crisp crashing sound.

"Can you do it...... This is already the sixth long-necked flask you've ever fried......" Qi Lin and 0592 watched from a distance in the other corner of the room - at first they wanted to get a closer look, but when the second explosion happened, the two of them had already dismissed the idea.

George himself was controlling the experimental process, and he could predict in advance when it would explode, but Qi Lin and 0592 couldn't, and when the first explosion occurred, the sharp glass slag even pierced 0592's eyes directly.

Fortunately, it was a pair of mechanical eyes, and the cornea was polished with high-hardness quartz, and it was also covered with a transparent metal coating.

"It's not a big problem......," George waved his hand, and took out a long-necked flask tightly wrapped in cardboard from his travel bag next to him.

"Isn't that a big problem for you? Is it only a big problem to be killed by the bombing? ”

"Uh...... The spirit of science is not to be afraid of failure, isn't it...... To be honest, I actually invented this 'developer' by accident, and as for the production process, it is still in the process of being perfected...... First of all, the temperature of this flame is very important, the temperature of this spray gun is difficult to stabilize, and it can't meet my requirements......"

"Temperature stable? It's easy to do, how high do you need temperature? Qi Lin asked.

"This step requires the silver to be melted, at least above 960 degrees Celsius."

"OK, Cortana, I'll leave it to you." Qi Lin snapped his fingers, and Thor's hammer walked up, pulled out a thermal axe, and placed the axe face in front of George, and then, the color of the axe surface began to gradually turn red, and the temperature around him slowly rose.

In addition to being used as a weapon to break armor, the task of the electric baking pan is also easily competent, and when he was on the front line, Qi Lin had seen armored soldiers use thermal axes to heat food.

"Cortana, what is the surface temperature of the thermal axe now?"

"962 degrees Celsius."

"Is that okay?" George was stunned, but he quickly got into the groove and poured the new reagent onto the face of the thermal axe, which had several oval-shaped grooves that acted like the blood grooves on the dagger, so that the thermal axe would drain the melted metal liquid along the grooves as it slashed through the metal armor.

The fine pieces of silver quickly began to melt as they fell into the grooves, and then George poured several other solutions that had been prepared and stirred them gently with a quartz rod.

"Okay, okay, cool down! Cooling! ”

"How much?"

"It drops to 350 degrees Celsius first, and then slowly and quickly drops."

George stared at the mixture in the groove of the axe's face, and waited until the state of the mixture gradually stabilized before he spoke again: "From now on, it will take thirty seconds to lower the temperature to room temperature, or it will drop quickly." ”

The surface of the thermal axe gradually returned to its original metallic color, and the mixture within the grooves condensed into a gray solid mass.

"Is this your 'developer'? Is this a success? ”

"It's done, it's done—" George said happily, using a dagger to pry the solidified reactants out of the groove and toss them into a large beaker filled with purple liquid on the table.

As soon as the reactant touched the purple liquid in the beaker, it instantly began to dissolve, and a large amount of gas came out of the liquid.

George hurriedly grabbed the sealing lid and put it on top of the beaker, and then said to Qi Lin and 0592: "Quick, we have to hurry to the side of the car where the incident happened, the shelf life of this thing is not long!" ”

……

……

The trio and Thor's hammer quickly rushed to the carriage where the body of the attacker had been found, only to see George poke a hole in the beaker's sealed lid with an awl, and the gas inside quickly gushed out of the small hole—

After this gas diffused into the air, it gradually revealed a trace of purple red, which extended from the bathroom to the outside of the carriage.

"After the 'developer' volatilizes, it will combine with the special smell left by the blood clan in the air, causing the colorless gas to turn purple red, and with this clue, we can find the blood clan!" George said.