"It's because you're asking the wrong questions that you're not finding the right answers."
One morning, just after breakfast, Malfoy was trying to kiss up to Cassius. He'd had detention the night before with Professor Moody and couldn't sneak out to see what the other schools' champions were up to – Moody worked him hard, and he was exhausted from moving those heavy boxes without magic. Cassius didn't have anywhere particular he needed to be – he had a free period just after breakfast – and was absentmindedly following Malfoy over to the Gryffindor table.
"...and I bet I could make Potter attack me. I almost got to him a while back; it was just bad luck that he got Goyle with his curse. Still, seeing Granger's teeth grow like that!"
Cassius, for his part, tried not to smile. Granger's parents were dentists, and didn't trust magic to realign their daughter's teeth correctly. It was a constant joke among the Slytherins, particularly after Granger conveniently neglected to tell Madam Pomfrey when to stop shrinking. As though her parents wouldn't notice when she went home for the summer holidays.
When they arrived at the Gryffindor table, they found the Creevy brothers still working on magically changing one of Malfoy's badges – he smirked when he saw that it now read Potter REALLY Stinks. Was Granger not interested in fixing the badges? Cassius saw one on her robes that said SPEW. Maybe she's just letting the boys have their fun. No harm in letting them experiment when Madam Pomfrey's around. Malfoy and Potter started bickering with each other, the usual banter between arch-rivals, when something caught his attention.
Potter pointed toward Cassius and mentioned "Oh yeah? I didn't see him see the Dragons last night." Dragons?
"What are you babbling about, Potter?" Malfoy said, before Cassius could react. "Why would there be dragons at Hogwarts? Did your half-breed pal Hagrid bring another egg to hatch?"
"Not this time." Potter said, glancing at the head table. Cassius followed his gaze and saw that Professor Moody was watching the conversation with both eyes. Karkaroff and Madam Maxime, who normally ate with the teachers, were not present. "They brought dragons for the First Task."
Cassius was interested now. He could handle a dragon, depending on the particulars. "And you know this... how?"
"That's not important." Harry said hurriedly. Hm, something he didn't want to get out, it would seem. "Karkaroff was caught leaving, and Hagrid took Madam Maxime there on a date. The other champions will know by tonight, if they don't already, but I didn't see you there. I thought you'd have snuck out to see what was up."
"I was going to, but Professor Moody had me in detention until eleven last night moving heavy boxes without magic." Cassius smirked. "I'm sure you know how exhausting that is, coming from those muggle relatives of yours."
Strangely enough, Potter didn't visibly react to that. Malfoy took this as his opportunity to jump in and start insulting Potter. Since Malfoy was driving, as it were, Cassius started thinking.
Can I handle a dragon? Their scales are tough and magic resistant – which means you need to hit them where their scales can't cover them. That means getting them in the eyes. The conjuncitvitus curse usually works when dealing with dragons, so I should make sure I practice that one. Why did Potter tell me about the dragons? It's to his benefit to leave me in the dark. No, right, he's got that habit of being a goody-two-shoes; he can't leave things well enough alone.
"I don't have time for this." Potter said, somewhat loudly, bringing Cassius back to reality. "Arguing with you isn't worth being turned into a small furry animal." He stood up and left before Malfoy could regain his composure. By the time he had, Potter was long gone.
Cassius looked at Malfoy. "Well? What do you think?"
Malfoy snarled. "I think I need to sneak some forget-for-now potion into tonight's pumpkin juice. Can't anyone forget about that stupid ferret thing?"
"I meant about the dragons. You know, the ones I'll be facing in the first task?" Draco Malfoy, the Amazing Bouncing Ferret. The newest joke in Slytherin House. Thank you, Alastor Moody.
"You believe him? You're the – you and – he's your competitor!" Malfoy was somewhere between absolute confusion and absolute horror. "He's going to lie at you if he thinks it'll give him an edge!"
"Okay then, aside from the competitor thing, why do you think he's lying?" Cassius was genuinely curious about this. Malfoy had more experience dealing with Potter than the rest of Slytherin House combined – and he usually came off worse for it. Surely he had some basis for thinking Potter was lying.
"You have to ask? He's friends with that mudblood Granger and that blood-traitor Weasley! He claimed that Black is innocent! He snuck his name in the Goblet and won't even fess up to it! He upstaged you! He won't say why he knows about the dragons! I can't see how anyone can believe that 'Saint Potter,' given his record..."
Cassius tuned him out. Aside from Potter being evasive about why he knew about the dragons, this was an old rant about how Potter doesn't behave like a pureblood, about how the wizarding world should be ashamed of having a know-nothing lowborn as its savior from the Dark Lord, and about how Potter snubbed him back on the train in their first year. Nothing in this rant actually indicated that Potter was lying about the First Task.
"...he's a muggle-loving half-blood. A disgrace!" finished Malfoy.
Cassius took this moment to ask Malfoy something that had been bothering him. "Well, what does it mean to be a pure-blood, then?"
Malfoy was gobsmacked. "You... you're a pureblood, you should know already! We're the natural rulers of mankind! Wizards, given power to reshape reality, are naturally superior to muggles, and by our blood we will direct the world! And those of purer blood are greater rulers!"
So, the Standard Death Eater Drivel, then. "That sounds a lot like what your father said when I asked him. Yet that 'muggle-loving half-blood' defeated the greatest wizard of the past century – twice, by his account. How can we be naturally superior when our best gets beaten by one of their babies?"
He only meant to shut Malfoy up, but now that he was saying it there was something there that, clearly, the younger Malfoy hadn't thought about. "I... er..."
"What? Your daddy never told you the story about how Harry Potter defeated the Dark Lord as a baby?" Cassius picked up his belongings and started to leave. "I suggest you ask him. In the meantime, let us assume that Potter is telling the truth, and that I should prepare myself to face some dragons for the First Task. Even if it's not actually dragons, I'll still have practiced some rather powerful and nasty spells. I lose nothing by believing Potter."