This is a traditional cache.
There is no puzzle.
Just go out to GZ, have a look around, and sign a piece of paper.
Of my last 26 caches published, 23 have contained a puzzle of some sort, be it in the field, or one to be solved at home.
That is 88% puzzles!
For some people, this is good, for others, not so much.
Of all my 64 caches published so far, excluding this one, only 18 of them have contained no puzzles
That is 72% puzzles.
Perhaps the puzzle here is why there is no puzzle at all.