Scarlett should visit the Hooded Wings guildhall and ask Master Deimos to join the guild. He will send Scarlett to see Grimm down in the catacombs to get an initiation task. Grimm will give Scarlett this quest.
Scarlett is told to go to the basement (1) and find Grimm (2), who is apparently the guild's coordinator of deliveries. He will tell her to deliver a letter to a customer (Hod, though Grimm doesn't name him) who is waiting on the rooftops of the Outer City across from the Old Temple. Scarlett is also told to reach the meeting spot through the Outer City Catacombs.
- The Hooded Wings - Grimm will only ask Scarlett to deliver a package for him if she has previously gotten "The Hooded Wings" quest from Master Deimos.
- A Lantern is highly recommended, along with some oil.
After speaking with Grimm (marked with a green (2) on the map), Scarlett should continued deeper into the catacombs. After a right turn and a little hip-deep waiting in water, Scarlett will pass an inanimate skeleton lying against the wall. Since she will not have yet acquired The Whisper necromantic skill, she can't do anything with the skeleton at this time. Another right turn leads her to the entrance of a larger cavern (3).
There's a trick to the route here (3): It's important that she stay left and go into the water rather than walking onto the dry platform. Swim left (Scarlett automatically begins swimming when she enters water.) Swim along the cavern wall until she comes to a small opening. Walking here and continue into a larger hallway, turn right and walk up onto a dry platform with a door. That door will (surprisingly) take our up to a balcony high on the outer city rooftops. (Click on map to enlarge.)
Out on the balcony, she will find Hod waiting. Just give him the letter.