Schiller passed the key through the cave entrance. After Bruce got it, he unlocked the lock, but of that entire wall, only that small section of bricks was loose; the rest could not be smashed open. So they still could only move around in their two rooms.
Schiller observed the structure of the opposite room through the opening. It was actually very simple. That side was a water prison. The whole room was relatively sealed, and water could only be released at the sluice. On his side, there was a drainage pipe in the corner diagonally across from him, so the water released over here flowed straight away.
The whole puzzle-solving process was not particularly difficult, but it required both sides to trust each other completely and possess a certain spirit of self-sacrifice.
The normal process on Schiller's side should have been: feel behind the only bed leg he could reach to find the key, use the key to pry at the bricks, pry the bricks open, then have the person opposite pass over the crowbar, use the crowbar to smash the bed leg, and after the bed dropped, pull down the lever so the water was released and the person next door was saved.
As for Bruce's side, he had been completely submerged from the start; otherwise, he would not have been unable to speak. There was also a water outlet continuously pouring water in. At the very least, they had to progress to the point where the bricks were dug open and a certain amount of water was drained first. If they were too slow, he would drown, and once he drowned, there would be no way to pass the crowbar over. Then it would be very difficult to break the bed leg, and the game could basically