"Go on, then," Hector said with a wry expression. "What is the truth?"

"The truth-" Papyrus started, and William abruptly bolted from the table, spilling his still-unfinished cup of hot chocolate before Debbie could catch it with her magic. Papyrus' hand lashed out, and suddenly William found his exit blocked by magical bones, and Papyrus summoned more to form a cubic cage around him. It wasn't actually made of bone minerals; a human could have broken through it easily. "HEY! YOU'RE SUPPOSED TO WAIT UNTIL I'M FINISHED ACCUSING YOU! THE NERVE OF SOME PEOPLE!" Papyrus switched back to his lawyer voice. "Anyway, as I was saying, William is indeed the culprit. And he is not what he appears to be!" Papyrus continued with a flourish. The figure in the cage began to writhe and twist, changing forms and desperately trying to squeeze between the bones before finally giving up and settling on its true form. The insectile Changelouse, only a foot and a half long, began chittering nervously. Vanna Carslyle clutched her pearls at the sight. Debbie was speechless, but her lip began quivering.

"Tell me," Robert said, frowning. "How did you know? Can you sense humans or monsters?" The Dreemurrs' abilities were common knowledge. If Asgore or Toriel had been there, the situation would have been resolved at once; they could have told the difference just by hearing it breathe. Asriel would have known even before getting out of the elevator.

"OH NO! I DIDN'T EVEN KNOW WHAT A HUMAN WAS THE FIRST TIME I SAW ONE!" Papyrus blurted before switching back again. "I refer, of course, to the curious incident of the footprints left in the mud!" Papyrus couldn't believe his luck; he was actually getting to quote Sherlock Holmes!

"What footprints?" Bruce asked, staring at the Changelouse.

"That was the curious incident!" Papyrus replied, widening his mouth enough that everyone could tell he was grinning. "Consider! It had rained enough to make fish happy on Thursday!" Papyrus could name one fish who was happy about it. He turned to Max, still grinning. "The culprit had escaped across a dirt field in pouring rain, and yet you did not know which way he went!"

Max scowled. "I knew something was wrong. He wasn't flying, he was running. But he was too light to leave deep footprints, is that right?"

"Correct!" Papyrus replied. "He's very light indeed!" He turned to the group. "So he eats light, too! Human children, no matter how much breakfast they've eaten, don't just order a cup of hot chocolate at Grillby's and nothing else!" The human children at the table had been stuffing their faces; the food was delicious. "I doubt he ate anything this morning with his dad- he might not even have one of those!" A lot of Papyrus' clients didn't have dads either, although not in the literal, monster sense.

"That's not right! I saw his dad!" Debbie replied, still confused and shocked that her friend would do this to her, tears in her eyes. She'd known he was a monster, but he'd told her that his family looked exactly like humans and wanted to keep that a secret; he'd never changed forms in front of her.

"Have you ever seen his dad and him at the same time?" Papyrus asked, and she realized. "And that old guy who 'pointed out which way he went' was him too!" he said to Max, who nodded angrily. "That's right out of the playbook for shapeshifters. If there is such a playbook. I think William could write one. And he laid a trap for you," he quietly said to Debbie. "That friend you went to meet yesterday was him?"

"Uh-huh," she hesitantly said.

"Who else would know that you were leaving, and could set the trap right before you left?" Papyrus asked gently so she wouldn't cry, but she cried anyway.

"Why?!" Debbie asked the creature. "Why would you be so mean and pretend to be my friends?!"

"I saw you with them on the bus," the monster complained in a startlingly human voice. "You were hanging out with them, and not me! I didn't want you to keep being with them! You're my only friend, so I should be your only friend too!" The Changelouse thought this was a perfectly reasonable thing to say, but nobody else thought that.

Max rose from the table, fists clenched, ready to earn some EXP. "She's still just ten years old, you psychotic piece of-"

"DON'T DO A VIOLENCE!" Papyrus shouted, holding up a bony hand. "IT DOESN'T THINK LIKE YOU THINK IT THINKS. IT'S REALLY INNOCENT EXCEPT FOR BEING GUILTY." Grumbling, Max sat down, still glaring at the creature. "BESIDES, KING FLUFFYBUNS CAN DO WHAT HE WANTS TO BAD MONSTERS, AND THIS ONE MADE TORIEL VEXED! BUT IT'S JUSTICE, NOT DUSTICE." Papyrus was worried that he might be lying. The human justice system had problems dealing with unruly monsters (who were fortunately quite rare); in response, Congress had basically given His Majesty total legal control over monsterdom. Asgore hadn't yet fed any offenders to Charles, but the option was always open.

The group finished their food before leaving, and Papyrus made a solid effort of slurping down spaghetti noodles even without having lips.

The next day, a rather unwholesome high-resolution video, starring a notable anti-monster activist and a traumatized duck, was posted all over the internet. The man denied everything, but his face had been clearly visible.