Create secret passages simply and easily via map regions.
All you need to do is enable the plugin and mark the path of a secret passage with the correct passable map region. Depending on the region used, player is either visible or invisible. To block the player from wandering of the path (in larger areas), use the impassable region. All three regions are configurable (defaults are 1 for visible, 2 for impassable tile, 3 for invisible).