Hey all you code-breaking, cryptology-loving millennials out there –- you know who you are -– the U.S. Navy has top-secret puzzle for you to solve. You’ll have 18 days to figure it out from serial clues served up via social media and, if you’re a true super sleuth, you’ll save the world.

Well, not exactly because the digital game is fiction, as is the backstory of a Dr. Evil-style villain who has stolen the plans for a high-grade Navy weapons project. A Navy cryptologist has stowed away on the getaway submarine, headed to “a secret island lair,” and will post encrypted messages each day. Players will have to decipher her increasingly obscure clues, figuring out the location and destination of the sub and ultimately catching the shadowy bad guy.

Along the way, participants can help each other with the various brainteasers and check in with a number of fictitious characters through their fake social media footprints.

The game, dubbed Project Architeuthis, launches Monday on the Navy’s cryptology and technology-centric Facebook Page. Posts have hinted at the game already for the page’s nearly 17,000 fans, where at least a few on-the-ball etymology buffs have noted that the game’s moniker means giant squid. Could that be a clue?

Project Architeuthis comes from the Navy’s ad agency Lowe Campbell Ewald, intending to act as a commercial and awareness builder for the military branch and to boost its social media activity. Executives at the agency have seeded the game with current and retired Navy cryptologists, and worked with New York-based puzzle-writing experts Puzzability to craft the script and clues.

The game comes after an earlier attempt to engage cryptologists, said Lowe Campbell Ewald Associate Creative Director Eric Bookout, in which the agency posted an alphabet-based Vigenere cipher on Facebook.

“Someone solved it in about five minutes,” Bookout said. “The gauntlet was laid down.”

Bookout says that Project Architeuthis will be no cakewalk, even for hackers and encryption specialists. Executives working on the project studied the work of Cicada 3301, an anonymous group that has released complex social puzzles for reasons that no one seems to know. Hacker recruitment, perhaps?

The goal of the Navy game is to educate the public about Navy career opportunities in this field, when most people may associate the Navy solely with its high-profile SEALS and sniper teams.

“We’re not capturing data, so it’s not a direct recruitment tool,” Bookout said. “But we’d love to see it become a real competition. And if people think it’s a cool game, maybe they’ll walk away with a positive image of the Navy.”

Winners –- there will be 10 -– don’t actually get prizes. But they’ll have bragging rights and some kind of title, like “champion,” Bookout said.

“People who are into encryption and puzzle-solving want the recognition,” Bookout said. “So they’ll be identified as the elite players who beat everyone else.”