Mortise deadbolt bypass?
If you look, it looks like the cylinder moves that piece that sticks into the hole where the cylinder goes, which is somehow linked to the bolt, so it turns the bolt.
Underneath the cylinder-hole, there's that ]-shaped slot/channel, and it looks like its purpose is to keep you from moving the bolt directly without using the key/knob.
Now, the hole that the bolt comes out of seems to have enough space above the bolt that you could stick a tool in between the doors, through the gap above the bolt, and pull on the part sliding in the ]-shaped slot, allowing you to move the bolt directly.
Now, I don't have one of these locks to try this on, could someone confirm/deny whether this is possible?