Draco said to Hermione, "Forget it, honey, you can't reason with this guy. He only believes his own version of things."
Hermione nodded and said, "I know."
"He can understand all the principles put in front of him, but understanding and agreeing are two different things. Thousands of years have already engraved his belief in his bones and blood, and it cannot be shaken by a few words."
Draco said no more, getting straight to the point, and said firmly, "Now, Marcus, tell me what you know about William's location and how to release him."
Draco stopped wasting words with him.
Marcus knew he had no choice but to speak; otherwise, the wizard would resort to force. But speaking was also not an option; if he did, the wizard would find ways to restrict him and prevent him from finding William.
But the current situation left him no choice.
In the end, Marcus could only reveal. "Back then, after capturing William, Viktor secretly had Selene's father build that prison. Viktor also kept the exact location of that cell a secret from me. I couldn't find it either."
"So, how do you open the prison?"
Marcus shook his head as well. "Only Viktor knows this. He oversaw the entire construction of the prison, and he kept all the details of the mechanisms a secret from me."
"You old codger, still playing dumb with us? Looks like we'll have to teach you a lesson." Trillian didn't believe it at all.
"No need for torture. I do know that opening William's cell requires two specially made round keys."
"I knew you wouldn't tell the truth."
"I know there's a key to open it, but only Viktor knows what the key looks like and where it's hidden."
"I don't believe you. You're such a liar, how can anyone know which of your words are true and which are false?"
"There's nothing I can do if you don't believe me."
Just as things were at a stalemate, Hermione seized on Marcus's unusual behavior and said, "You definitely know more than that."
"When you went to the wolf's den to retrieve the corpse, it wasn't just to appease the vampires. That was merely a smokescreen; there must have been something on the corpse."
Marcus had no choice but to admit, "Yes, my purpose wasn't just to appease the vampire people, but to get Singe to complete her experiment. Viktor, as one of the three elders, has a body and blood that are of great research value."
Trillian, struck by this remark, instantly realized something and sharply exposed her. "Stop using experiments as an excuse! You're after the key, aren't you! That key must be hidden on Viktor, and the moment you retrieved the body, you had it!"
Marcus knew he could no longer hide it and could only confess, "Yes. When I retrieved Viktor's body, I did indeed take a specially made round brass key from deep inside his chest."
Trillian held out her hand. "Give me the key."
With the situation hopeless, Marcus knew that struggling any further would be futile, so he took a key from his pocket and tossed it to Draco.
Draco caught the key and examined it closely.
The key was nearly a semi-circular disc, not a perfect circle, and about the size of a finger in diameter, with thick edges.
On the flat side, there are interlocking tenons and mortises.
So that's what the two keys meant.
It needs another half to make a complete key.
Trillian leaned closer for a look and continued to question:
"Why is there only one? Where's the other half?"
" Viktor only has this one on him. With that cunning personality, how could he possibly hide both keys on himself?" Marcus was much more composed this time.
Draco examined the key, then had another thought, "Forget it, we don't know if this key is real or fake. What if you fooled us? Wouldn't that make us look stupid? So, just to be safe, you should drink the potion."
With that, Draco tossed the potion to him.
Marcus took the potion, thinking to himself: This is what they call the Veritaserum; it looks no different from ordinary water. I wonder if my body can withstand it...
If the medicine takes effect, I'm afraid I'll have no other chance.
But I can't not drink it.
It would be embarrassing to be forced to drink it then.
Marcus had no choice but to uncork the bottle and tilt it.
They outwardly adopt a compliant posture.
However, in that instant, Draco silently chanted the Depulso Charm, drawing the potion from the vial. The liquid transformed into a thin, silvery thread, moving with incredible speed, and was sent straight into Marcus's mouth.
Marcus's expression changed drastically, his disguise crumbled, and he could only grit his teeth. But the magic was incredibly fast, and the potion instantly slid down his throat and into his stomach, making him appear completely unharmed.
Marcus's apple bobbed almost imperceptibly as he swallowed hard. His previously calm expression turned ugly, his eyes filled with anger and humiliation.
He was still forced to confess.
Seeing this, Trillian scoffed, crossed her arms, and glared coldly at him:
"I knew you wouldn't give in so easily, you old codger. If I don't push you, you can keep this up forever."
Draco ignored his embarrassment and asked again, "Alright, how many keys are there to open William's prison?"
The effects of the truth-telling drug forcefully broke through his pretense, his brain's instinct to resist lying tugged violently. Marcus's apple bobbed, his teeth clenched, but he had no choice but to utter the truth. "... two. Two semi-circular copper keys, fitting together as one, neither can be missing."
Draco held up the key in his hand:
"Is this one real or fake?"
Marcus gritted his teeth, forcing out the words: "... Fake. It's a replica, a complete fake. The appearance, texture, and even the patina are all copied; it's indistinguishable to the naked eye."
Trillian immediately laughed and mocked, "Good heavens! You've lived for a thousand years, and your mind is even more cunning than a fox's. I think you'd be better off as a thousand-year-old fox than the progenitor of vampires!"
"Bring out the real key."
Draco gave the order directly.
With things having come to this, Marcus could only reach into his hidden pocket, take out the half-circle copper key, and, filled with resentment, throw it away violently.
Draco caught it, glanced at it, and asked, "Now tell me, was the key you just threw out real or fake?"
"... This one is genuine."
Draco nodded, handed the fake key to Trillian beside him for safekeeping, and continued to press, "Where is the other key?"
"... with Lucian."
Draco and the others were all surprised.
But Veritaserum doesn't lie.
Hermione asked:
How did the key end up on Lucian?
Marcus replied, " Viktor entrusted the key to his daughter for safekeeping, and later the key ended up with Lucian."
Hermione then asked, "Do you know where the prison is?"
"Have no idea."
Does anyone else know?
" Selene..."
Hermione asked, puzzled, " Selene? How did she know?"
What she didn't understand was,
If Selene knew, she had no reason not to tell.