How to Get the Silver Ankh in "Stonekeep"

1). Approach the Spiker. He will advance toward you.
2). Backtrack, facing the Spiker. Retreat one pace past the portcullis.
3). Face right. Retreat three paces.
4). Let the Spiker pass through the portcullis and into the same space as you.
5). Turn so you are facing in the opposite direction. The Spiker will follow.
6). Retreat three paces. Face left. Retreat one pace. Face left again.
7). Hit the button on the wall that controls the portcullis. The portcullis will slam shut, trapping the Spiker.
8). Head west until you reach the wall. Take one step south and one step through the false wall. You will see the Silver Ankh at your feet.
9). Pick up the Silver Ankh.