In Nancy Drew: Treasure in the Royal Tower, to get to the tower, the first step is to obtain Dexter’s key to the library. Change the time to late at night, when Dexter’s gone from his post. Head downstairs to the lobby desk and snoop. Find the library key in the little drawer, then walk through the first floor halls to the elevator and library door. Call the elevator to the first floor, but do not go in. Turn around to face the library doors, and unlock them with your key. The alarm will sound, so take two steps forward, then rotate back to the alarm panel by the door. Press 3*72 to disarm it. Cross the library, step upstairs, crawl through the air duct, climb down into the elevator shaft and open the metal grate. You can now walk below the elevator and continue on.
