If you are trusting to your feet, then leave the ship and walk for a day down the road until you reach the town of Poseidon. If you prefer to take your day's exertion in other forms, my friend, then I suggest you hail a ride from one of the vehicles that goes between the Old City outside of the great ship and the town. Not all of them belong to the authorities.

[For some reason, Zevran's getting the sense that Jayne's not a law and order type. Aren't assumptions cruel?]