The adventures of Humboldt Brecht and his friend Fatty Melhuish initially appeared on the MSN Group/Community Addicted to Discworld, specifically in the thread The Missing Room. They are collected here to save them from being lost as the thread turns over. Although there are those (probably) who feel this would be a desired outcome.
Humboldt 1. Humboldt Makes a Splash
Humboldt 2. Humboldt Delivers
Humboldt 3. Wayzgooze