From the introduction:
With Maris out of sight and certainly up to more trouble the group must track him down somehow to ensure that he does not become a threat in the future. His ties to the false Cortani family and Elia, the only other known member of the family, are the only two leads the PCs have to follow, and the Cortani family had its fingers in dozens of pies. Searching through their holdings the PCs find nearly a dozen businesses, including a bakery, warehouse, apothecary, exotic store, and shipping company that are more than what they seem. After searching the places of business the Cortani family owned the group will unravel the threads of a plot much larger than simply spreading madness around a few merchants or nobles. With the larger picture in hand they will confront Elia as she flees the city and finally learn where Maris is hiding.