Bring a mysterious artefact to your sorceress friend to learn more about it.
The Witcher 3: The Nobleman Statuette
This quest is very similar to The Soldier Statuette. Both need to be attempted before Triss Merigold leaves Novigrad as a result of Now or Never, if you do not successfully romance her.
The mission is triggered when you buy the Jade Figurine quest from the merchant across from the Gilford noticeboard near the St Gregory's Bridge signpost.
Bring the statuette to Triss in her lodgings or at the Rosemary and Thyme. She escorts you to The Bits and casts a spell, revealing a very confused nobleman. Send him on his way to complete the quest.