You look at the door but see no lock. You listen at the door but do not hear anything. You do not see any traps so you open the door. It opens into a room that is 30 feet square. You see nothing in this room it is bare of anything. In the middle of the left wall is another door. The door is barred shut as you can see the bar being held in its two brackets on each side of the door.
Once again I'll listen and check for any traps. If there's nothing, I'll shake my head at the door design and say, "I'm going to be severely disappointed in these people if there isn't a bar lock of some kind on the other side I can't see. There's little point in a door bar if people can open it from both sides."
Out of Character: How wide of a gap are we talking about between the door and its frame? If a centimeter or so, I'd just have two people slip long daggers in there and lift. If If narrower, a bit of wire shaped into a 'U' attached to some twine would let me get a loop around the bar.
Out of Character: The door you just opened into the room is not barred. The door on the left wall is barred on the rooms side. Looking through the small gaps around the door you do not see anything as it is dark out there. You would have to lift the bar up and try the door to see if there is a bar on the other side or find a way to get some light in the area beyond the door.
I will follow after the others, allow them to take the lead as I start looking focus because if not much happening. I will say, as Jason and Grant check out the door, "You know these tunnels seems pretty abandoned, or perhaps its occupants are all invisible? Its strange in how little life we have found except for George."
Out of Character: Ah, I misunderstood.
In Character: "It could just be a secured entry to what was once the front door to this structure, or if there was a threat, that threat might have been gone for decades given the state of this place. But yes, there might be an imminent threat beyond here. Let's be careful."
I'll get people to form up, ready to launch a volley at anything coming through the door. Then lift the bar, and open the door with my left hand.
The door opens in towards you with ease. You can now see a corridor that runs straight. As you follow this corridor it soon turns to the left. As you follow that corridor it comes up to a side passage to the right. Rolls please for everyone.