word - Piece de Resistance - Two Boxes, Two Boxes of Letters

Two - Boxes, Two Boxes of Letters

_{This puzzle is part of the "Piece de Resistance" series. Go back to Part 1 (Ace) for the story.
Ace Two Three Four Five ...}

_{Out of Character: Finally, a working... !}

Once again you rub away the sivery coating, and you found a diagram:

Answer

With a friendly nod to @jafe (who came very close), since an hour has gone by I figured it was fair game to post my own independent solution… Didn't want to be seen as sniping or piggy-backing!

This is indeed a:

WorDonimoes puzzle, and has a solution in 17 moves.

As follows (double moves abridged in the diagram - read along each row; moves in square brackets can be carried out in an alternative order):

Using the hint (“\ \”) and interpreting the title to imply that we are looking at two boxes of nine squares side by side, we should read down their diagonals to see the answer:

LASHES