Cracked wall

The Cracked Wall is an environmental object in Baldur's Gate 3. It exists in the rafters of Moonrise Towers and can be found on the main floor and interacted with after using a ladder to climb up to the rafters.

Involvement

The cracked wall is the source of the "suspicious sounds" noted by Mig might be uncovered. A DC 14 Arcana check tells the player character that the essence inside the walls is close to the one they felt on the Nautiloid. Interacting with the wall allows the player character to reach into the gap (at this moment the Dream Guardian cautions them against it, but the warning comes too late), where a tentacle grabs the arm of the interacting character and grips it tight unless they pass a check to free it.

• [STRENGTH] Tear your arm out of the tentacle's grip. (DC 14)
• [DEXTERITY] Wriggle your hand free. (DC 16)
• [ROGUE] [DEXTERITY] You've been in tougher traps - wriggle your hand free. (DC 16 )
• [RANGER] [DEXTERITY] Calm yourself and gently wriggle your hand free. (DC 16 )
• [MONK] [DEXTERITY] Twist your wrist to break the grip. (DC 16 )
• [SLEIGHT OF HAND] Go limp and ride it out. (DC 14)
• [THE GREAT OLD ONE] Invite the presence in. There's always room for one more.

Failing this check or doing nothing (for  Warlocks, selecting their unique dialogue option, too) allows the tentacle to grip the arm and communicate directly with that party member. The party member is then able to talk directly to the "Absolute". If they are the Dark Urge, the presence recognizes them and calls them "disgraced master" and "the fallen one <who> returns". Eventually, the tentacle attempts to grip harder and the party member has to make another ability check to avoid being pulled into the depths:

A character communicating to the mysterious presence

• [STRENGTH] Heave against the tentacle with all your might. (DC 21)
• [BARBARIAN] [STRENGTH] Channel all your rage - and pull. (DC 21 )
• [DEXTERITY] Search for some leverage to slide your arm out. (DC 21)
• [MELEE ATTACK] [MELEE ATTACK] Forget subtlety - claw at whatever you can reach. (DC 0 )
• [WISDOM] Focus your thoughts to an edge - and cut free. (DC 21)
• [PALADIN] [CHARISMA] Channel your oath. Rebuke the voice. Free yourself. (DC 21)

Failing this check or doing nothing results in the tentacle dragging the whole party to the Oubliette beneath the Moonrise Towers Prison. Regardless of the result the interacting party member receives a  Dislocated Shoulder injury in the process. Interacting with the tentacle grants the following inspirations:

•  A Different Kind of Muse ( Entertainer background)
•  Delving into the Deep ( Outlander background) - if being dragged into the Oubliette
•  They're in the Walls! ( Sage background)