Use other game pieces to help you solve the chess puzzle going to the royal tower. If you are in Junier detective mode, it isn't hard to move peices around. However, it will be alot harder on Senior detective mode. I managed to get past that puzzle on Senior detective mode by moving the blue peice, the green peice, the pink piece, then the white piece. I'ts exactly the same on Junior detective mode just without the white piece
When you go into the basement throug the elevator, look up, and climb through. Next, go up the ladder for a little while, and find the vent shaft on the left as you go up. If you can't go any further, you've gone too far. Go through the vent and open the shaft door at the other end. Make your way halfway down the stairs and then go back up the moment you here Dexter comming in, make your way back into the shaft, turn around to listen and see Dexter talking to himself, and when Dexter leaves, go down the stairs again to explore.
Green Medallion: In The ski lift in the shed
Red Medallion: In the garden
Blue Medallion: Under a pillow in Pro. Hotchkiss's room
When you put the medallions in the right order on the floor in the tower the diamond appears. Lisa appears, she sprays pepper spray on you, and then she fesses up. She runs down the stairs while she is too busy runing you should see a gray sqaure, click on it and Lisa falls in the dungeon!!!
Also you can take the paintbrush where Jaque Brunais usually is. But go there when he isn't there. Then go through the vent to get to the library and put the brush on dust and dust the alarm. For details go to your magazine in your room