2. The upper left library (which needs magic to open) kills boss to get the red crystal.

3. Collect red and blue crystals, and kill boss from above the map to enter Figure 4.

4. Obtain the prism (see Figure 4 for details) and return it to the Silver Knight to obtain the treasure key.

5. Get the treasure house key and go straight to the right to open the treasure house and get the sewer key.

6. There are two transmission arrays at the lower right of the map. Take the rightmost one, open the sewer and enter Figure 5.