In Nancy Drew: Shadow at the Water’s Edge, you will need to solve the master nonograms puzzle in the hidden baths. To get both sets of numbers, you will need to open the frog safe in Yumi’s apartment, and solve the origami fold found in the bamboo deer scare in the garden.
Once you have found the hidden baths, you can use the two pieces of paper with numbers to solve this master nonograms puzzle, also known as the lattice puzzle. Right-mouse click on the squares to place an X in the spot, and left-mouse click to fill the spot. You can reset the entire grid and start over by clicking the red reset button to the right.
Refer to the video for the complete answer.