Our last puzzle of 2017 is by Brendan Emmett Quigley, and it's a meta. "Gear Change" is 4/5 difficulty.
Here is a note: "The meta solution to this puzzle is the cause of the issues in its grid. Send the solution to firstname.lastname@example.org by the end of 2017 for a chance to win a special prize in the new year!"
We're fortunate to have you as solvers and friends, and we send our love and thanks!