Use a Charter ship to Port Phasmatys; talk to Bill Teach on his boat in Port Phasmatys at the east end of the dock near the Green Ghost Inn. Agree to sail with Bill to Mos Le'Harmless. You may opt to use the Mos le'harmless teleport scroll, or to use the Trouble Brewing minigame teleport. Near the dock, you will notice a rather sickly-looking monk named Brother Tranquility. Talk to him to begin the quest—select the option regarding undead pirates. He will explain how some of his fellow monks are in trouble and asks for help. Accept the offer to be teleported to Harmony Island.