Where is the key of Nafa in The Wizard 3: wild hunt?

There is a bridge on the left of the mill. There are two water ghosts. After killing the water ghost, you will find a body. Take out a key from the body and open the box in the water next to it. There is a military order in the open box. After reading it, you can go back to the ground and open the box.

Wizard 3: wild hunt is a role-playing game produced by CD Projekt RED and released by WB Games (North America) and Spike Chunsoft (Japan). The game was released on Windows, Playstation 4 and Xbox One platforms on 20 15 and 20 19. The game is adapted from the novel The Devil Hunter series, which is the third game in the Wizard series and the finale of Geralt's adventure.

Game plot

After Geralt regained his memory, he began to look around for traces of Ye Naifa. Finally, Yenefa contacted Geralt, whom he hadn't seen for many years, and asked Geralt to meet him in Willoughby village.

However, when Geralt arrived at the designated place, the whole village had been razed to the ground by the army, and Yenifa had disappeared. On the way, Geralt met Vesemir, and with his help, he tracked the trail of Ye Naifa together. On the way, Geralt dreamed of what happened to Kyle Mohan. This dream warned Geralt that his adopted daughter Healy had some problems.