Book Four - "The Seedy Part of Town"
Part One - "The Maze"
The Twisty Little Alley is an alley. It is north of the Via Sacra. Instead of going west in the Twisty Little Alley, try going south. The description of the Twisty Little Alley is "This is a maze of [if a random chance of 1 in 2 succeeds]little twisty[otherwise]twisty little[end if] alleys, all alike."