What to know
- The Paranormal Investigator challenge requires you to photograph Gentleman Ghost.
- Gentleman Ghost does not appear normally in the open world.
- You must stand on a hidden ectoplasm puddle in East End — Amusement Mile.
- Opening Photo Mode while standing on the puddle makes Gentleman Ghost appear instantly.
The Paranormal Investigator Batcave Challenge in LEGO Batman: Legacy of the Dark Knight can be confusing because the game never clearly explains how to make Gentleman Ghost appear. Many players search the Arkham road for several minutes without realizing the ghost only spawns under a specific condition.
Here is everything you need to know to complete the challenge quickly:
| Challenge | Objective | Location | Requirement | Reward |
|---|---|---|---|---|
| Paranormal Investigator | Photograph Gentleman Ghost | East End — Amusement Mile | Stand on ectoplasm and enter Photo Mode | Challenge completion and Batcave progress |
Where to find Gentleman Ghost in Gotham City
The challenge takes place in the East End district, specifically around Amusement Mile on the road leading toward Arkham Asylum. This area is part of the open-world Gotham map and becomes accessible while exploring the city.

As you travel up the road toward Arkham, keep an eye out for a small glowing puddle of green ectoplasm near the roadside. The puddle is easy to miss because it blends into the environment and Gentleman Ghost is completely invisible until you trigger the event. Community reports and gameplay clips confirm this hidden trigger mechanic.
How to complete the Paranormal Investigator challenge
Step 1
Travel to East End — Amusement Mile and head toward the road leading up to Arkham Asylum.

Step 2
Slow down near the first bend in the road and look carefully for a green ectoplasm puddle on the ground.

Step 3
Stand directly on top of the puddle. Nothing will happen immediately, which makes many players think they found the wrong location.

Step 4
Open Photo Mode while standing on the ectoplasm.

Step 5
As soon as Photo Mode activates, Gentleman Ghost will suddenly appear in the frame.

Step 6
Take the photograph to instantly complete the Paranormal Investigator Batcave Challenge.

Why Gentleman Ghost does not appear normally
The game treats Gentleman Ghost as a hidden paranormal encounter rather than a standard NPC spawn. The ectoplasm puddle acts as a trigger zone tied directly to Photo Mode. Until you activate the camera while standing in the correct spot, the ghost remains invisible.
This design appears to be part of the game’s environmental puzzle system used throughout Gotham City’s open-world challenges.

Rewards for completing the challenge
| Reward Type | Details |
|---|---|
| Batcave Challenge Progress | Counts toward overall Batcave completion |
| Completion Tracking | Advances open-world challenge progress |
| Exploration Reward | Unlocks another Gotham collectible activity |
The Paranormal Investigator challenge is one of the more creative open-world secrets in LEGO Batman: Legacy of the Dark Knight because it combines exploration, environmental clues, and Photo Mode mechanics into a small detective puzzle. Instead of fighting enemies or solving gadgets, you are rewarded for noticing subtle details hidden in Gotham City.
Once you know the ectoplasm trick, the challenge only takes a minute to complete, but discovering it naturally can be surprisingly difficult.