There are multiple new bounties from Spider. This Where To Find Wanted: Subterranean Mind In Destiny 2: Forsaken guide will tell you where to find the single Wanted Bounty currently available on the planet Mercury.
The new Wanted Bounties are unlocked through speaking with Spider, at his new hub, and trading him special new currency items, Ghost Fragments. Once you have the required number of Ghost Fragments you can choose one of the many weekly bounties to take, giving you an objective to hunt down and kill a powerful enemy.
Head to Mercury, you need to travel to Pariah’s Refuge. The entrance is marked by the special door icon on your map, the small set of arches. They are also present on nearby stonework and other objects to hint at its location.
You can find the entrance by traveling to the exact location of my character on the picture above. Once there, follow the tunnel all the way through. You will reach a large room filled with enemies. Clear a few enemies and the Wanted: Subterranean Mind will spawn in the middle of the room.
Defeat it to complete the bounty.