3:00 p.m., Friday, Jan. 16Upon finally attaining the sixth floor of the Massachusetts Institute of Technology's Building 24, I first notice the shoes. There are pairs and pairs of them lining the hallway leading to the double doors that gate the way to the Manic Sages' headquarters. The second thing I notice is that on the wall of this hallway is a map of Middle Earth. The chatter of the shoes' owners can be heard through the doors, indicating that Mystery Hunt 2009 is in full swing.

In 1980, MIT graduate student Brad Schaefer organized the first Mystery Hunt, and it has only grown since. In the competition, teams of puzzlers of high-school age and up from all over the world solve puzzles to locate a coin hidden somewhere on the MIT campus. The tradition began after Schaefer sent his first hunters after an Indian-head penny in a marathon themed problem-solving event. Since its humble beginnings, Mystery Hunt has grown into a thousand-person odyssey that sometimes lasts for as long as three days.

This year, Hunters were stranded in the fantastical Zyzzlvaria and needed to perform tasks to "meet the Brass Rat Crew," headed by Captain Blastoid, and "activate the Covertly Operated Inversion Node." The prize? The privilege of writing and running next year's Mystery Hunt, as well as the bragging rights of being the best of the best the Hunt had to offer.

3:42 p.m., Friday, Jan. 16

Ben Swartz '12 had just text-messaged Asaf Reich '12 with a little friendly ridicule on behalf of his team, Codex Magliabechiano: "You are going to lose." Reich, a first-year member of the Manic Sages, reunited with Mathcamp friends, many of whom only see each other once per year. Catherine Havasi (GRAD), one of the organizers of the Manic Sages, ran around with a clipboard, a jaunty black hat and a nametag that said "Puzzle Pimp," trying to enforce as much order as she could on the chaos of churning mental cogs.

I teamed up with Reich and Havasi as a member of the Manic Sages, a team composed of Hunters from diverse social groups such as members of MIT's Experimental Study Group and Canada/USA Mathcamp, a summer program for mathematically gifted teams that fosters as much friendship as it does interest in math. This team was large, nearly topping 100 members, but nobody was a stranger.

This was the first Mystery Hunt in which Reich and Swartz had ever participated, and, as Swartz wrote in an e-mail to the Justice, "I'm pretty much going in blind." (About a day into the Hunt, Swartz remarked to me that the experience was "a bit harder than I expected.") Reich also had no high expectations for his first hunt but remarked that he relished any experience that brings Mathcamp friends together.

Swartz and Reich may have been taking on their first Mystery Hunt, but Havasi was a veteran. After participating in her first hunt as an MIT first-year in 2000, Havasi joined the Sages about five years ago. She brought her organizational and mental skills to what she described as "much more boring things" than actual puzzling, "like figuring out where everyone is going to sleep, designing a team T-shirt and preparing food for the weekend." But Havasi's leadership role on the team did not interfere with her adherence to the Manic Sages' "have fun" mantra: "Fun is very important to us, and I think it actually helps us be competitive," she wrote.

I settled down to work on a puzzle titled "Interstellar Basic Algebra" and almost immediately heard raucous cries and applause that indicated a puzzle had been solved. The Hunt had been on for almost four hours.

7:30 a.m., Saturday, Jan. 17

I meant to wake up at 6:30 a.m., but I overslept. I left the sleeping room (team members often sleep at MIT until the competition ends) and nipped back to the sixth floor of Building 24. The room smelled of mental effort and sleep deprivation, the same odor that our library takes on during finals period. I joined those who had not slept yet in more puzzle-solving.

As the Manic Sages' wiki says, "For us, the Mystery Hunt is a social occasion as much as it's a puzzle-solving competition. ... If in the process of having fun we solve loads of puzzles, more power to us."

This motto showed. Floating among the puzzle solvers, I saw T-shirts identifying Scrabble champions, math champions and students from a dozen universities. People were constantly laughing and congratulating each other. There was even a celebratory air guitar solo after the team obtained the Wheel of Death, one of the components needed for the escape from Zyzzlvaria.

6:43 p.m., Saturday, Jan. 17

Swartz instant messaged me to let me know that he had finally solved a puzzle that had taken him and his teammates over five hours to complete. I congratulated him, then turned my attention back to the puzzle I was working on, called, "The Satellite of Love." As Reich pointed out, some puzzles-like "Micronauts," a first-round puzzle that was not solved until Sunday-provide too little information, while some provide too much. "Satellite" was one of the latter.

Mystery Hunters recalled favorite puzzles fondly. Swartz once worked on a puzzle for a non-MIT hunt that "had something to do with food eaten by a Facebook clone of Neopets," the popular online game. After spending about two hours playing the game to find the solution, "another team member ... walked over and gave us a suggestion. ... It is interesting how stepping away from your puzzle and looking at a fresh one really advances both puzzles."

Dan Zaharopol, another team organizer, Mathcamp alumnus and very veteran Hunter, recalled in an e-mail to the Justice that his favorite puzzle, "Abducted!", was a Yahoo!Maps odyssey to which the solution was the Kyrgyzstani flag. "I ... think the idea of pictures as solutions to puzzles is pretty neat," wrote Zaharopol, who jokes that his goal for this year is "to get a very close second place" so as to avoid having to write the next Mystery Hunt. "More seriously, I want to have a good time puzzling and for everyone else to have a good time. I'm a compulsive organizer and always worrying about how to make it more fun for others."

8:00 a.m., Sunday, Jan. 18

I left the Hunt to return to Brandeis, but dozens of people were still working under the snow that began to blanket Cambridge. The competition was not projected to end for hours more.

At about 3:40 a.m. Monday, Swartz and Reich called to say that the Hunt had finally ended "rather anticlimactically," as Reich put it. Swartz was right; Manic Sages did not win, but neither did Codex. A new team called Beginners' Luck finished the Hunt first and won the coin for Mystery Hunt 2009, which fell short of the record for longest hunt ever by a mere five hours. Codex may have come in fourth, but Swartz said with enthusiasm that "I would definitely do [Mystery Hunt] again!" He summed up a friend's description of the Hunt as "like a puzzle video game that you'd buy at a store but much more complex, much more awesome and much more fun." I have to say I agree with Swartz; Mystery Hunt was nothing if not complex, awesome fun over one exhausting weekend.