Decide to give the pendant to either Jeanette or Therese.
Jeanette will be immediately available after returning to The Asylum.
Therese will appear at The Asylum after completing the quest Slashterpiece.
This section is incomplete and requires expansion.
Update: Upon receiving quest:
Therese has asked you to go to the Ocean House Hotel and search for a personal item of the spirit that haunts the place and bring it back to her. The only way to get to the Ocean House is through the sewers.
You retrieved the pendant from the Ocean House to bring to Therese as payment to convince her to call off her feud with Tung.
Update: If the Pendant is not given to Jeanette:
You retrieved the pendant from the Ocean House to bring to Therese as payment to convince her to call off her feud with Tung, but she wasn't at The Asylum. You should check back later to talk to her when she returns.
Update: (Alternate) If the Pendant is given to Jeanette:
Therese wasn't available, so you gave the Ocean House pendant to Jeanette - probably not the best of ideas. You should check back later to talk to Therese when she returns.
Update: (Alternate) Speaking to Therese after giving the pendant to Jeanette:
Jeanette threw the Ocean House pendant - the one you stupidly gave her - into the ocean, thereby thwarting Therese's plans to exorcise the spirits haunting the hotel.
Update: Upon completion:
You gave the Ocean House pendant to Therese, as per her request.
Ocean House Front Door Key
Boiler Room Key
This quest contains the only moment of daylight in the entire game, when the player picks up the pendant.