While the spell discussion is cool, remember that you’re still currently being chased by shitloads of guards. At your current pace, they’re catching up, and are not far behind; going fast enough to evade them also means going fast enough to attract the attention of every civilian who can point the soldiers after you.
Getting out of sight for a bit somehow would probably be a prerequisite for any illusion disguise to work.
On the map at GURPS Banestorm PBBB narrative thread - #2 by Wanderfound Safiya Square is #63, the Grand Mosque is #62, the Palace is #58 and Southhall is #60. You’ve just left Safiya Square on Al-Imaan Street heading southeast.
The southeast part of West Tredroy is its quietest, most residential bit. Southbridge (#66) is closed to commercial traffic after dark. #67 is the docks, #64 is the Mayor’s place.
