SOLUTION TO

The Case of the Purloined Princess

"Clearly, an MIT student helped Bowser escape," announced Sally, as Peach and Mario joyfully embraced.

Sally explained, "The water glass that we found on the table had the shape of a beaver melted into it.  The "brass rat," or MIT class ring, will melt ice into a beaver shape just from body heat and firm application of pressure.  One nervous wedding guest, waiting for his opportunity to help the dastardly hound wreck this joyous occasion, pressed his ring into the ice cube."

"Um," said Encyclopedia.

"Also," added Sally, "Bowser was clearly lying when he said he had never been down the Infinite Corridor, because there was no other way for him to enter the chapel without passing one of us!"

"So..." began Encyclopedia.
    "Bowser was a Harvard student," finished Sally, "because he was still holding a grudge from the time MIT hacked the Harvard-Yale football game.  And his necktie was actually crimson, not red."
    "Oh, um," said Encyclopedia.  "I knew that."

    And that is how ENCYCLOPEDIA BROWN solved The Case of the Purloined Princess.

with a little help.