-This is a (BD style) magic wall. It gets activated for about 10 seconds by
-rocks or gems that fall on it. Rocks that fall through it become BD style
-diamonds, and gems that fall through it become BD style rocks. After it has
-stopped running, it cannot be activated again.
+This is a BD style magic wall. It gets activated for a limited duration by
+rocks or gems that fall on it. While activated, they can fall through it, and
+rocks turn into BD style diamonds, and gems turn into BD style rocks.
+After the magic wall has stopped running, it cannot be activated again.