Tacit Brook
A Protocol Space containing the unknown. Explore it properly and you might find some operator promotion items.
"Thus you shall face your inner self. Feel its strengths and weaknesses, and touch its joys and sorrows."
Dungeon Info
TypeProtocol Space
SeriesProtocol Space: Promotions
Rec. Operator Lv.Lv.20
Stamina40
Mechanics
Natural SP recovery is much slower. Skill-based SP recovery is greatly increased.
Enemies
Rewards
Operational EXP ×240 Operational EXP ★★★★★ Raises the Endministrator's Authority Level. 
Protodisk ×8 Protodisk ★★★ A material that promotes operators to E1 or E2. Overview › Tips on Defeat
1
In this Protocol Space, try to use skills with SP recovery.