Overview

The Underpass Resonant is the fourth hunt in the Defeating Resonants questline (per the source quest list). Dylan has found a spire-like structure in the Underpass that appears to be made of Astral material — and something Resonant waits at the top.

Starting location: The Underpass Zone, at The Spire. Requirement: you must have reached the Underpass as part of the main quest Recursions and Iterations.

Objectives

  1. See Where the Spire Leads
  2. Investigate the Astral Plane
  3. Kill the Astral Plane Resonant

Walkthrough

Starting the quest

After unfogging the map, zoom in to see the text "The Spire". Stand north of The Spire and inspect the "eye" icon with L1/LB to add the quest to the log — or simply climb The Spire and it starts on its own.

See Where the Spire Leads

Left of the fast travel door, use the Gravity Shift ability to climb the side of The Spire (the red blocks). At the top, defeat the enemies blocking the way; once they're down, the red blockage turns into a bright white light. Go through it to reach the Astral Plane.

Investigate the Astral Plane

On the Astral Plane, climb up, then jump over to the side of the floating path and immediately use Gravity Shift to latch onto the wall and walk up it. At the end of the path is a locked door. To open it, jump to the three flying islands around the area — each holds a key at its end, and all three keys are needed to reach the Resonant. The keys can be collected in any order:

  • First key: the island directly across from the locked door (the far end from where you first climbed up)
  • Second key: the island to the right of the door
  • Third key: the island to the left of the door

Kill the Astral Plane Resonant

With all three keys, open the doors and reach the boss. Defeat it, then use the button prompt to finish it off. Afterwards pick one of two abilities — Spike or Astral Rebuke — changeable any time later in The Gap via the Mural.

Rewards

  • Ability choice: Spike or Astral Rebuke (changeable at the Mural in The Gap)
  • Untapped Golden Earrings artifact
  • 1 Reset Item
  • 3,000 Source

What it unlocks

Continue the questline with The Park Resonant, then finish with The Unknown Resonant.