Disclaimer: I in no way own Detective Conan or Magic Kaito, and make no profit from this work other than the restoration of my mental facilities now that the plot bunnies aren't gnawing on my brains....
This, honestly, was all driven by that first image. First word, even. I was expecting it to be longer, but apparently Kid is too crafty for me, too.
Ah, and as for the Snake/Jackal thing. We're just going to pretend that it's a different alias for the purpose of this one-shot. While that's an easier route than I usually take, I really can't think of better explanation. In the Magic Kaito manga, it's Snake. In the Detective Conan OVA, it's Jackal. While I don't think most people really care and this is probably just a case of canon-lapse, the best reason I can think of is for Snake to employ more than one codename. It's not that uncommon for criminals, right?
"Taaaaaantei-kun!" Kid crooned, the split-second of panic lost in the drawn-out vowel to become the thief's usual vaguely amused tone. "Fancy meeting you here." Great, my two biggest threats in one night. Hakuba's not going to show up, too, is he?
"Kaitou Kid," Conan said simply, that blasted watch aimed right at him.
Kaito quickly took stock, Poker Face slamming a grin on his face. No hat to help hide his identity, no cape to even fake a getaway (since there was no way he could leave without Aoko noticing his absence – and he had to return the jewel anyway), and he was reasonably sure the only reason that the brat hadn't darted him yet was because the thief was still more than halfway out the window, one hand holding the rope ladder Snake had used to reach the train's roof, body turned to block the wind from the young prince supported in the other arm and hanging from his neck.
In short, this sucks.
"I don't suppose you'd be willing to let me drop off le petit prince and go my merry way?" he tried, stalling as he tried to figure out how he could pull off getting the kid back to his mother before returning the jewel and without ending up unconscious. Maybe a flash bomb, did he still have a flash bomb?
The brat just smirked. "Well, I might agree to the first half of that." Conan's face got thoughtful then, glancing to the spots normally occupied by the magician's hat and cape. His hands didn't move, though. "What happened up there, anyway?"
"Worried? I'm touched, Tantei-kun." No, because they had been in his hat. Cards were out, given the state of his gun. Knock-out gas? No good, it'd get the second brat, too, and that'd ruin Operation: Queen of Hearts. He didn't have any doves tonight, either. So that left... what? Smoke–
"Please, Conan-kun!"
Both thief and detective started, looking at the child in Kid's hold. Prince Phillip still had his arms around Kaito's neck, but he had twisted around to face the miniature detective. "Kid-san isn't a bad person!"
Kaito frowned. "Hey, wait a sec...."
The prince wasn't listening. "Kid-san could have left with the jewel if he wanted to, but he didn't! He tricked the scary ojii-san and saved me even though he didn't have to!"
Hell, but this kid was too perceptive. One would think all the time he'd spent with Tantei-kun had taught him not to underestimate little kids, but.... Good thing being a prince is a full-time job; last thing I need is another up-and-coming detective.
And Tantei-kun was smirking again. "Oh really," he said, arching an eyebrow. That face was wholly too amused at the situation for a seven-year-old.
Kid did his best to look mortified – which is to say, he looked very mortified indeed. "Oi, oi," he said, admonishing the prince. "I'm supposed to be the bad guy, remember? You'll ruin my image saying things like that." The prince only laughed, making Kaito roll his eyes before looking again at the detective, who still hadn't lowered the watch. "Listen, Tantei-kun–"
"Conan-kun!" came a female voice from the hall, neatly severing the thief's attempt at speech. Conan flinched, instinctively looking behind him to the room's open door. Kaito seized the chance, leaning into the room and safely depositing the prince before going back out the window, drawing the rope ladder up with him to discourage Tantei-kun from following while he got the hell outta Dodge.
Conan had no sooner realized the trick of the thief throwing his (or rather, Ran's) voice than he was at the window, catching sight of the ladder as it was disconnected and left far behind. There was no trace of a white suit. The shrunken detective's face, however, wasn't even playfully upset; he just flashed that too-old smirk at the train roof.
The same grin appeared again in the train station when he saw the Ingram royal party walk past, gigantic topaz in its proper place hanging from the queen's neck.