You just need to destroy the lever that is next the walls!
A really well-made campaign, I must admit, not comparable to most other examples made these days. On the other hand, it has a ton of grammatical errors. And by a ton I man a LOT. I'm afraid, it's useless for me to report them, you only need to read each sentence carefully and you will find mistakes in half of them. I'm tired of exclamation marks followed by commas!,
On the other hand, I'm not sure if it will ever be updated, just hope v2.0 will be better in this respect. I r8 8/8!,