-This is a (EM style) magic wall. It gets activated for a limited
-time by rocks or gems that fall on it. Objects falling though
-it will be changed to other objects. After it has stopped running,
-it cannot be activated again.
+This is an EM 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 emeralds, emeralds turn into diamonds, and diamonds turn into
+rocks.
+After the magic wall has stopped running, it cannot be activated again.