The party ventured into the Haunted Coast, and stumbled upon a set of cages and torn down and broken banners featuring a wolf skull with its maw open. They discovered that vampires had set prisoners free so they could hunt them down, like a game of chase and to feed. After following a trail, they found multiple piles of ash, and three prisoner corpses. Something had killed the vampires and potentially the prisoners there. After trying to find a straggler who left the area, they found a cabin with some surviving prisoners, a half elf, a Yaun-Ti, and a Hobgoblin. They explained the situations to the best of their ability, how they were taken off the road and made prisoners for these Vampires. After defeating some fledgling vampire spawn, a brief dark silhouette along the clearing edge that moved fast when chase briefly. The party then focused on saving more prisoners, finding a halfling and a Goliath with the former being the friend and travel companion to the Yaun-ti. They stated that they were able to defeat a vampire, but were jumped and almost killed by a larger threat before hiding.
The party got all the NPCs saved to Tower Haven. What killed the Vampires is still out there.