Tactics?

Hey, we tried to close the door and cast a silence, but it seems that I couldn't lock or wedge the door, and these 5th level guys doubted the silence into non-existence. Cutting the bell cord had no effect either.
And Dude, I just no-save, attacked myself twice for 18 points of damage. When your spells don't work and both you and your opponent are attacking yourself, it can really bum you out.
But, we'll plod on, no less; it's an adventurer's life.