Level by M@ster (Bartlomiej Baron)
Walkthrough by Vimmers
You need the revised english.dat and script.dat.
Start the game with The Lost Library.
You start in front of a closed blue door. Turn and use the jumpswitch, go in and pick up some flares. Dive and pick up the crowbar on the boxes. Swim into the opening south, climb out of the water and pry off the star. Swim to the wall east and use the star and the door in the east wall opens. Go in and swim to the east wall and use the lever to lower the water. Go down and use the green globe and you see a flyby of the door opening where you picked up the crowbar. (You can move the little globe but it doesn't do anything.)
Go there and swim into the south opening. Climb the pole, jump off and use the lever on the south wall. Go in and pry the star off its perch on the west wall. Go out to the pole room again and use the star on the west wall. An aggravating earthquake starts. Go in and go down the hallway. Go to the north wall and use all the jumpswitches. Dive in and get the Horseman's Gem. Go back to the pole room and locate the gem slot on the north wall. Use the gem there and the door in the north wall under the pole room opens.
Go there and locate a wall lever on the west wall. It opens the big doors. Go in and pull the globe 2 times back and you see a flyby showing the start area. Go there and climb the blocks. Go to the marked area and the game finishes.