The Odyssey (Side Quest)
In what should really have been named 'No Good Deed,' you'll pick this one up after the 'A Tithe By Any Other Name' quest. Find the priest, now hunted by soldiers and in fear for his life, in the dock area south west of the Serapeion.
Speak to him for a synopsis of the quest- you need to get him to temple in the north of the city.
Despite his words, you don't actually have to go by canal- he'll follow wherever you lead, and is exceedingly spry for his age. If you've already cleared out the Kibotos Arsenal (which you likely did during the Serapis Unites quest), then just make a beeline north to the Temple. The soldiers on the streets don't seem to take notice unless you actually collide them, but it's still wise to avoid such collisions by scouting ahead with Senu.
You don't actually have to take him all the way to the Temple- when you get far enough you'll receive a prompt to talk to the priest, who is suddenly just milling about. Speak with him for his wrap-up dialogue.
When that's taken care of, the quest completes.