A minor noble in Sigil, apparently a Bard of some repute, and a secret member of the Society of the Black Lotus. Lady Scarlet was wealthy enough to own her own villa and have a small retinue of liveried guards in her service.　Her exact role in the Black Lotus is still unknown, but her social position and wealth was obviously an asset to the Society.
Lady Scarlet lured the PCs into a trap, tricking them into attacking her villa and then calling the Harmonium watch patrol to arrest them. She was ultimately killed fleeing the PCs attack on the secret meeting with Guildmaster Brackett and Llamar, burned to death by a Flaming Sphere cast by Calonveriel. (See The story so far)
The Party found some useful information in her house afterwards.