Thanks. Well, I had a fallen tree which blocks an entrance. To remove the block the player needs a chainsaw. I just wanted a short cutscene of the player cutting into the tree, but I couldn't use the normal storyinzone script because it would activate regardless of whether the player had the chainsaw.
So I changed the storyinzone script so instead of the player being in the zone the zone entity just needs to be activated. Then I set my invisible wall to activate the zone before destroying itself. I was very shocked when it actually worked! I am a rubbish scripter and I've just come back after a long time without doing any Lua so this seems like a miracle.
Julian - increasingly disillusioned and jaded