Café de Nuit

I definitely like the James Martigan article! He makes a good NPC in general, but is an even better fit if I play up the legacy of Van Richten subplot.

Speaking of Van Richten, there's an adventure in Mordentshire that features him called "the Scarlet Kiss" (contained within the Chilling Tales anthology. A vampiress disguised as a Halan type wtch has infiltrated a hospice and is in the process of transforming him into a Vampire.

There is a fan-made adventure in the Library called The Wailing Sorrow that I think was set in Mordent. It's part one of an unfinished trilogy (I believe), but its got a lot of meat on it in terms of plot hooks that can be built upon to complete the story.