From House of Hozz
This is the "how the hozz brothers get to be in Faierie plot arc.
Before this plot arc, we need to have established Zack's necromancy, by way of Driving lesson. This gives Zack some motives to explore his new powers, seen in Zombie Fetch and Covert zombie operations.
The "evicted" story is next. By revealing the pit in the basement, the hozz brothers are evicted.
This gets them to move to a new house, which allows Oswald to install his magic new front door. Soon afterwords the door swap series occurs, possibly never being completely resolved by the characters themselves.
This should get the hozz brothers firmly entrenched in the world of the fay, during which time they should begin doing some initial explorations.