A window lock for securing a first window member against unauthorized movement relative to a second window member, the window lock including a bolt mounted for sliding movement in a drum journaled for rotation on a hub throughout an arc of rotation, the hub being affixed to the first window member and the bolt carrying a key and a latch engaged with a cavity in a housing affixed to the second window member throughout the arc of rotation of the drum when the bolt is advanced, the hub having a recess oriented for receiving the key of the bolt only when the bolt is located at a predetermined angular position within the arc of rotation where the key is registered with the recess to permit retraction of the bolt and corresponding retraction of the latch from the cavity, the orientation of the recess being masked from unauthorized view such that visual verification of the predetermined angular position of the bolt is restricted to an authorized operator.