At The Keeper’s Gate

You find yourself in the lane outside the Keeper’s house. Inside, there’s clearly quite a new year’s party still in progress – and judging by the small explosion followed by a loud cheer, some occasional alchemy too. You try the gate, and are surprised to find it locked – but then again, as the Keeper said before, most of his visitors just appear, rather than bothering with the front door.

Just as you start looking for somewhere to climb the wall – perhaps a bit risky in the slippery winter conditions – you notice a small piece of paper tied roughly to the gate. On it, you find a grid, with some annotations around the edge:

On the back are some instructions:

  • Fill in each number from 1 to 16 once.
  • Obey all rules.
  • Multiply reds, then add blue, then multiply by green.
  • The code is green then blue then the answer to your calculation.
  • Please close the gate behind you.

Why is nothing ever easy with that Keeper? Even his front gate is puzzling. You sigh, and fish around in your bag for a pen.