This spell enables a wizard to detect secret doors, compartments, caches, and similar devices. Only passages, doors, or openings that have been deliberately constructed so as to escape detection are detected by this spell- a trap door buried beneath crates in a cellar, an illusionary wall, or an amulet left in a cluttered room would not be detected. The wizard affects an area of 10 feet square per level, so a 4th-level wizard could search four sections of wall, floor, or ceiling.Any doorways or openings detected by this spell glow softly for one full turn. It's possible that a wizard might not find a secret compartment in the area of effect if the compartment is behind or under another object that covers it completely. This spell only detects the doorway or opening;the wizard may have to search for a mechanism or catch that opens the door.