These are two mutually-exclusive quests; you have to choose which one you want to do. You can only do one of them so choose wisely:
Option 1: Puritan Justice
Between midnight and 2 am or so, trek out to <a href="/mobs/details.html?id=160">Arthur Dimmesdale</a> and <a href="/mobs/details.html?id=454">Hester Prynne</a>'s trysting place in the woods. Make sure Arthur sees you. Go to the magistrate in the Law Courts near the southern gate. ASK MAGISTRATE HESTER. He will ask you if you are witness to her lover. SAY YES. He will ask who. SAY ARTHUR DIMMESDALE. Arthur Dimmesdale is summoned. The magistrate asks what you have witnessed. SAY WOODS. Arthur Dimmesdale is summoned. He'll talk to you and ASK DIMMESDALE HESTER. He'll prompt you again and then ASK DIMMESDALE SAW IN WOODS.
-> You get XP!
-> You get a red tunic!
-> You get a knight's Crest!
-> You get whois ...AIDED IN BRINGING A PURITAN MINISTER TO JUSTICE!
Option 2: Puritan Revenge
About midnight, wait in A Clearing in the Darkness until Arthur and Hester arrive. Leave and reenter the room -- Arthur should make an excuse as to their presence. Go to Roger Chillingworth in the Ordinary. ASK ROGER PRYNNE. He asks if you seen her. ASK ROGER YES. He asks where and with whom. ASK ROGER FOREST. ASK ROGER ARTHUR DIMMESDALE. He will order you to return at 2am the next day in order to take him to the tryst. Return at 2am the next day. UPDATE! -> You do NOT have to wait until the next day before leading Roger to the tryst. Just ask him to follow you right after you told him about Arthur Dimmesdale. ASK ROGER FOLLOW. He follows you and tells you to sneak do NOT need to sneak. Go to the trysting place. Once there Roger will tell you to return to the Ordinary. At the Ordinary he tells you to bring Dimmesdale to the cemetary at 6am. Wait for Arthur to return from his tryst. ASK ARTHUR FOLLOW. ASK ARTHUR CEMETARY. Arthur follows you. Go to the cemetary. (If you arrive before Roger, leave and reenter when Roger arrives.)
-> You get XP!
-> You get a silver feather!
-> You get a onyx ear cuff!
-> You get whois ...AIDED IN REVENGING A PURITAN MAN'S LIFE!
credit: <a href="http://www.legenddb.com">legenddb</a>
Option 3: Puritan Family
After you ask Roger Chillingworth about Hester and he says to return at 2AM, instead go to Hester and ask Hester escape. She will say 'from what'; ask Hester Roger she talks some more and then ask Hester he is coming. From there: follow Hester; once she stops ask Hester Arthur Dimmesdalethen ask Hester escape. She says to return at 11pm with Dimmesdale. Fine Arthur and ask Dimmesdale follow me, then ask Arthur Hester Prynne. When he follows you, go to Hester... some spam ensues.
-> You'll get XP
-> You'll get whois: ...aided in reuniting a Puritan family separated by fear.
-> You'll get a black shawl!
-> You'll get a scarlet letter!