Reach the Deep Docks and you’ll find a locked, ornate door sitting just beyond a lava gap. It’s one of four “Simple Key” locks scattered across Pharloom, and it’s easy to walk past if you don’t have the right movement ability. Here’s how to get to it, what you’ll open, and how to weigh it against the game’s other key doors.

What you need before you go

  • Swift Step: The lava gap in front of the door is slightly out of reach without the dash-run you learn elsewhere in Deep Docks. Grab the art first, then return.
  • One Simple Key: Keys are single-use. There are four in total across the game, and four locks that consume them.
Tip: Simple Key locks are optional. None are required for main story progression, so you won’t softlock your save by using one “wrong.”

How to reach the door (fast route)

  • From the Deep Docks Bellway sign, head right into the “enemy rush” room and clear the waves to open the path forward.
  • Continue right to a pool of lava with a platform just out of a normal jump’s range. Use Swift Step to run, jump, and land it.
  • The locked door sits on that platform. Use one Simple Key to open it.

What’s behind the Deep Docks door

Opening the lock reveals a sizeable sub-area under the docks: new enemy types, tight platforming over heat and lava, and multiple side paths you’ll fully clear later once you have the midgame hook-style mobility art. Expect hazards that hit hard (some foes deal two masks) and a few larger chambers that loop toward the far-right of Deep Docks.

The key early payoff here is Flintslate, a tool that temporarily adds fire to the Needle to boost damage, plus a Craftmetal pickup to build more tools. You’ll also see additional sealed doors and ring mechanisms you can’t meaningfully use until Act 2 mobility expands. Think of this door as early access to combat power and a partial alternate route, not a mandatory shortcut.

Note: You’ll still engage the area’s primary progression gate in the usual way. Treat the key door as optional content that dovetails back into Deep Docks rather than a definitive skip.

Is Deep Docks the best place to spend your first key?

It depends on your priorities:

  • Want immediate combat value? Use the key in Deep Docks to reach Flintslate and a Craftmetal.
  • Chasing exploration and a crest early? The lock northwest of Bone Bottom opens a Wormways shortcut and quick access to a crest reward.
  • Following an NPC thread? The cage in Sinner’s Road frees the Green Prince and starts a late-game questline beat.
  • Saving for later? The High Halls door leads to a dark “vault”-like side area with a money haul and a hidden tool; most players are better off opening this once you’re regularly visiting the Citadel.

Where to find Simple Keys (there are four)

  • Bone Bottom: Sold by Pebb (the earliest, priciest purchase early on).
  • Sinner’s Road: Dropped by a Roachkeeper encounter in the zone’s upper-right platforms.
  • First Shrine (Songclave): Sold by Jubilana after you complete the Wandering Merchant rescue; expect a higher price than Pebb’s.
  • Sands of Karak: On a corpse at the rightmost bench; this area opens up after you gain the Act 2 grapple.

Abilities that unlock more of the key-door areas

  • Swift Step: Required just to reach the Deep Docks lock across that lava gap.
  • Hook-style grapple (Act 2): Opens the rest of the post-door Deep Docks side paths and ring mechanisms.
  • Double jump (Act 2): Helps clean up the trickier verticals in both the Deep Docks side wing and Sands of Karak.

Quick walkthrough: getting Swift Step, then doubling back to the lock

  • Climb the central lifts near the early Deep Docks bench and work upward and left into the statue chamber to bind Swift Step.
  • Use the new art to reach a levered chain lift above, then a high platform path where you can free a Lost Flea; this also creates convenient loops back down.
  • Return to the enemy rush room, head right, dash-run across the lava, and use the Simple Key.

What to expect inside (spoiler-light)

  • Hazards: Narrow spaces, moving platforms, projectiles, and wide lava plates. Bring enough rosaries to buy a nearby bench activation when you find it.
  • Enemies: Fast chargers and projectile bombers that can double-hit; don’t face-tank. Use vertical space and Silkspear windows to control waves.
  • Structure: Several doors are locked from the far side or gated by later mobility. You’ll revisit this wing in Act 2 for complete cleanup.

The four Simple Key locks, at a glance

  • Wormways door (northwest of Bone Bottom): Shortcut and early crest pickup after a gauntlet through Mosshome and the spitter cavern.
  • Deep Docks: Optional sub-area with Flintslate, Craftmetal, and links toward the far right of the region.
  • Sinner’s Road cage: Frees the Green Prince; you’ll see the payoff much later.
  • High Halls door: Late Act 2 side route with heavy rosary rewards and a hidden tool behind a breakable interior.

Bottom line: if you’re stuck staring at that lava gap, grab Swift Step, commit a key, and take the win. If you’re rationing keys, Deep Docks is the best early choice for raw power, while the other locks are better framed as exploration routes (Wormways), a narrative thread (Sinner’s Road), and a late-game money-and-tool sweep (High Halls). None are missable for the story, and you’ll circle back to finish what your current kit can’t reach.