DD4 Secret of the Silver Spire is a classic-style fantasy RPG module for 1st edition rules (AD&D/D&D/OSR). In this adventure, the player characters explore an outlandish citadel inhabited by strange creatures, such as the barzani ape-men, modrons of many types, and three-faced golden sentinels. The enigmatic overlords are the "silver masters" — alien beings made of pure energy. The tower is a maze of rooms stuffed with strange equipment and curious items these creatures have collected from all over the multiverse. For characters levels 3-7.