Prophetizing during siege

[JimMorrison]

Apparently you people have never used secret escape tunnels. o.O

You can't run a train through them! If they were large enough to accommodate those sorts of activities, they'd be too easy to find. And if you tried to use them outside of a battle, you'd be spotted! You have to get the enemy army at the gates, ready to go - that's when you slip out the back door.