Dungeon23, Day 2

(I'm jumping the gun a little, getting ahead on this because I don't anticipate having time tomorrow night. Don't want to fail the challenge on day 2.)

 Room 1.2: The upper floor of the gatehouse. The eastern section has a Scorpion (treat as a Ballista, per the DMG) that can be pivoted to aim out any of three firing ports. Additional slightly smaller arrow slits allow for crossbow shots along other avenues of approach. 

The western section has a collapsed floor leading into area 1.1A, and the Scorpion that should be on this end is missing. 

Between the two sides is a middle section overlooking the bridge. It has two raised portcullises in this upper space, and the floor section between them has numerous murder slits for raining bolts downward. Note that the gears and winches for the portcullises also collapsed when the floor in the western section gave way. The grates are held in place by locks and wedges. If they were to be released, they would slam downward into place, and given the broken and missing winch system, there's no easy way to lift them back up.  (Lifting the now-jammed gates by hand in the middle of a battle is a Difficulty 25 Athletics check. Doing so with a group of people outside of combat is automatic, but takes several minutes of focused labor.)

This room is guarded by two Sword Wraith Warriors. 

(2x CR 3, per Mordenkainen's Tome of Foes) 

In life, these warriors were tasked with guarding the bridge, but when the castle was defeated by treachery and sorcery instead of by force of arms, they were trapped within the barbican and starved to death. They now wait eternally for the attack they were sworn to repel. 

If any of the PCs (or their allies) come from a distinguished family line with a famous coat of arms or long history, it's possible that these warriors will recognize their heraldry and seek to block their passage on the bridge. The same holds true if a PC returns to the surface with the magic shield emblazoned with the three black crowns on a red field (see room X.XX, below). In such a case, the portcullises come crashing down forever and the Sword Wraiths will sally out for combat, or fire bows or scorpion as necessary. 

Note as well that the Sword Wraith's special Martial Fury ability has great synergy with fighting on the staircase from 1.1B: they get the extra attack, and the Advantage it would give the PCs is canceled by the Disadvantage of fighting up the stairs. That would be part of these Warrior's trained tactics from their mortal posting to this tower, so it's definitely a tactic they would attempt to utilize from beyond the grave. 

Treasure: Scorpion (if you can disassemble it), 20 large bolts for the same, 14 electrum pieces dating to the era the castle was built in, and the weapons and armor on the Sword Wraiths.

(The missing scorpion and winches from the western section can be found in room 1.3, below.)