[Radek]

1. You are coming to the elevator puzzle - go STRAIGHT.
2. You are entering next elevator room - go STRAIGHT.
3. You are entering next elevator room - push the lever and return using the same elevator.
4. You are entering the previous elevator room - take the elevator to the SOUTH.
5. You are entering next elevator room - take the elevator to the NORTH.
6. You have fallen into the Serpent's Master room. Deal with the Serpent's Master. Push the lever. Take the elevator to the LEFT. It takes you to the room with the first lever. Use the key and open the hidden door there. (The elevator to the right takes you to the first elevator room.)

Notes:
1. Do not throw the key away immediately! It also opens the bars you have seen during your way to the elevator maze. After opening the bars you can throw the key away.
2. Take a bit of paper and draw 4 crosses on it. Two crosses in the first line and next two ones below them. The entrance to the maze is the first cross in the upper line from west. Take the elevators and mark which elevator takes you where: select an elevator, mark it on your paper, take the elevator and add the same mark on the place where you emerged from the tunnels below and above the elevators. The tunnels are "two ways" and they always connect exactly two elevators. Therefore, your scheme will not complicate. You will have the maze solved soon and once for all.