The puzzles were later collected and compiled into a book in 1980, but, soon after, disappeared—until now. The cryptic crosswords have been scanned and placed online, and Sondheim, himself, has taken a look to confirm that they are, in fact, his.

In Sondheim's introduction to the book of puzzles, he describes the cryptic crosswords saying, "This kind of puzzle offers cryptic clues instead of bald definitions, and the pleasures involved in solving it are the deeply satisfactory ones of following and matching a devious mind (that of the puzzle's author) rather than the transitory ones of an encyclopedic memory."

The website offers copies of 19 puzzles, along with solutions, rules, and the introduction by Sondheim. To put your mind to the test, click here.