Photo by FishFeathers

The October issue of Smithsonian magazine is devoted to the “Secrets of American History.” It’s also a mind-boggling scavenger hunt by the hand of Ken Jennings, the game-show contestant and puzzle-master who pulled off a 74-show hot streak on Jeopardy! in 2004.

The full puzzle is available only to subscribers or people who buy a print or digital copy of the issue, but aside from a vital first clue in the magazine, the other 11 puzzles are online. They must be tough, because the contest will run until the first reader submits the correct final answer. In a press release, Smithsonian says there will be false clues, red herrings and a whole lot of head-scratching.

The first puzzle involves cracking a code—available here—that invokes the “greatest creation” of Thomas Jefferson, whose digitized portrait graces the cover of the October issue. The code, if deciphered, will reveal a password that should help one solve the rest of the puzzle. As for Jefferson’s “greatest creation,” the hint offered is a dead giveaway:

Remember that Jefferson, as a man of letters, always measured his words carefully, so you’ll need to do the same. As you’re reading, a hint: When first, finish with Honor.

It’s a not-so-subtle reference to the Declaration of Independence. The codex that follows? Beats me.

The first person to solve the entire puzzle gets a trip to Washington and a special tour of the Smithsonian Institution.