Ghost Story Island is the 23rd island in Poptropica. It was scheduled for release as the first new island of 2012, on January 12, 2012. The quest involves discovering the secrets of Hemlock Harbor and its 5 historic ghosts.
This solution contains all spoilers. See the related link below for a video walkthrough.
Cemetery / Main Street / Inn and Haunted House
(Main street includes the Gingerbread House Bakery, the Bank, and the Hemlock Herald paper)
1. If you go right, you will find that there are no rooms available at the Inn.
2. Go left past the Visitor Center (multi-player room). If you stop at the newspaper, the Hemlock Herald, you find that the editor is offering a reward for ghost sightings (there are some spooky things going on at the paper itself). In the Bank, they are closing up, and the Vault is closed except for deposits. At the Gingerbread House, a man with salt will give you some "to chase away spirits." Go left to the Cemetery.
Cemetery and Herald and back
3. Meet a tour guide offering tours of the "Celebrity Spirits." The Magistrate has prohibited ghost hunting in the town, and when he appears, the tour guide leaves. She drops a pamphlet that lists information on the 5 historic ghosts in the town.
-- The Tireless Thief (the bank)
-- The Cemetery Specter (the cemetery)
-- The Woman in the Window (haunted house)
-- The Restless Lighthouse Keeper (lighthouse)
-- The Warden's Sweet Tooth (island prison)
(You cannot pursue any of them until you have the proper equipment.)
4. Near the cemetery gate is a young man trying to find his uncle's burial plot. He asks you to research the archives at the newspaper. Go there and go down into the basement to open the Archives. The uncle, Silas Moon, is on page 4 and is listed as Lot C, plot 84. Take this information back to the man at the Cemetery and he gives you his room key at the Inn.
Discomfort Inn - *The Woman in the Window
5. Go right to the Haunted (Discomfort) Inn and check in at the desk. Go up to room 2-B. You will lie down and fall asleep. But you will soon wake up to discover that things in the room are moving!
6. Go to the cabinet and open it, to reveal that the two Inn owners are playing a trick on you. But they insist that the Woman in the Window is real, and that she will appear if music is played.
7. Go downstairs and now you can pick up the Violin next to the piano.
8. Go out and right to where a ghost hunter has set up his tent. Use it to bounce up to the Haunted House and use the violin. Slide the bow back and forth until the entire song is played. You will see some faint activity at the upper window.
9. Climb down to see the ghost hunter. The Magistrate will arrive and take him away. Use his binoculars to look up at the house. You will see a figure in the attic window.
10. Bounce up again and enter the house through the metal basement door.
11. Go left, but the stairs collapse. Push one or both of the wooden crates under the stairs so you can jump up.
12. Cross the room, go up the interior stairs, and enter the door to the second floor.
13. Use the telescope to see the bay (turn the ring on the outside to focus). You can see the island prison and the lighthouse. Suddenly a voice behind you says "Looking for Someone?" (This is spoken dialogue, not a speech balloon, so it may spook you! Sound is rare on Poptropica.)
14. It isn't a ghost, just an old woman who offers you information. She says to tell the bakery owner, Jane, that "Fiona sent you." Exit the house and go there.
Gingerbread House Bakery
15. The baker, Jane, is actually a secret ghost hunter. She will provide you with a thermal scanner, an EMF detector, a thermometer, and a camera. Each piece of the equipment will flash at the lower left of your screen when it is time to use it.
16. Look on the table to the right and click on the plate to get some Hot Cross Buns. Exit the Gingerbread House and go left, all the way to the Cemetery again.
Cemetery - *The Cemetery Specter
17. Click on the gates to enter the cemetery. This entrance is marked with the letter H on the "maze view." You will have to navigate through the maze by clicking the "ahead" arrow or the "turn" arrows to change direction.
18. Make your way to the upper right of the map and you will find a gate labeled "B" and then to the upper left where there is gate marked "A" (from this point on, you can go there just by clicking the letters A, B, or H on the map).
19. Go through gate A and go to the right. Jump on top of the large grave and get up on the hill. A woman ghost hunter will appear and tell you to hide, and soon a robed figure will appear carrying a rose. Use your camera to get his picture.
20. Leave Lot A and go across to Lot B. There is a weird ghost hunter who is trying to detect the sounds of ghosts. Leave him and enter the Engraver's shed. He has little to say at this point.
21. Exit the gate and click on the H to leave the cemetery, and go back to the Herald.
The Herald and the Bank - *The Tireless Thief
22. Talk to the editor at the herald and she will give you 50 dollars for the photo of the Specter. Take it to the bank to deposit it.
23. As the bank is closed, go down to the vault and see the guard and his dog Rusty.
24. When the guard enters the vault, Rusty begins to bark. Use the thermal imager to examine the vault and you will see a glowing form beneath the vault floor.
25. Exit the bank and go to the Herald, where a special edition of the paper features your photograph. Click on the stack of papers to see the headline. A group of the ghost hunters has gathered. The Magistrate arrives and disperses them.
26. At the same time, near the Haunted House, a small boat, the Kestrel, has come ashore. Go right to the beach to meet the boat pilot.
27. Give him the key to your inn room, and he will let you use his boat to travel into the bay. Click on "enter" to begin the boat view.
The Prison Island - *The Warden's Sweet Tooth (the Tireless Thief, part 2)
(the game seems designed to seek the ghosts in order, with the Prison discovered after the Lighthouse, and then a return to the Lighthouse when you try to go back to town)
28. Steer the boat across the bay (up and right) to the deserted prison. Climb up and enter through the doorway marked "repent."
29. Equip your EMF meter and search the prison using the elevator. As you go higher, the readings seem stronger, and you will reach level H, where the Warden's office is located.
30. Enter the office and you will see the desk chair rocking back and forth. Use the hot cross buns at the table and the warden's ghost will appear.
31. After eating the buns, the warden explains that he wants you to locate a prisoner who escaped long ago, leading to his disgrace. The prisoner was a forger sentenced to life in prison. His number was 24601 and his cell was on level D.
32. Go to level D, cell 8, and enter the cell. You will find a book that had a tool hidden in it, allowing the prisoner to dig his way out. When the warden locks you in, slide the bed to the right to reveal an escape tunnel.
33. Follow the tunnel. If you use the thermal imager, there is some sort of energy at the top right. Pick up the can of sardines, the pickaxe, and the note. The ghost of the prisoner will explain some of how he came to be there. For some reason, he was asked by a man named Henry Flatbottom to forge a note to a man named Valiant, who sailed from Hemlock Harbor and was lost in a shipwreck. When he escaped his cell, the tunneler could not dig through the metal vault floor and was trapped there.
34. Go back out of the tunnel, and use the pickaxe to escape from the cell.
35. Use the elevator to go back to section A, and leave the prison. Travel in the boat, across to the lighthouse (middle left side).
The Lighthouse - *The Restless Lighthouse Keeper
(the game seems designed to seek the ghosts in order, with the Prison discovered after the Lighthouse, but you can go to either, with only a little confusion, since the Lighthouse seems to send you back to the mainland)
36. Sail slightly up and left to reach the Lighthouse and dock there at the right side. As you enter, you acquire a torch to see through the darkness inside.
37. Light your torch at the burning one at the foot of the staircase.
38. (The Windy Staircase) You will have some difficulty going up because a strong wind blows down the stairs at regular intervals. You can see it blowing leaves as you go up. You have to duck down for the entire time that the leaves are moving. If you stand in the wind, the torch is blown out and you are tossed to the bottom of the stairs. The easiest way is to move one bit at a time, no more than a dozen steps, then quickly duck (crouch down) until all of the leaves have passed. Then quickly make your next move and duck again.
39. At the top, jump to the rope and climb to the room below the searchlight.
40. To detect any ghosts, use the thermometer sensor by placing it on the wall. Now if any ghosts come, it will alert you to the colder temperature.
41. Climb the broken ladder at right to reach the outside of the tower.
42. Turn on the searchlight and examine the bay. There are reefs at the upper left, and a large building (the prison) at the far right. You can now leave the lighthouse, and the fastest way is to jump down to the water or onto your boat. Sail the boat up back to the beach at right and dock there.
43. As you land, the thermometer goes off, and you return to the lighthouse.
44. As you enter, an invisible ghost carries a torch up the stairs. You can follow because there is no wind.
45. In the room, you meet the ghost of the Lighthouse Keeper, who fell asleep and allowed a ship to crash into the reefs. Exit the lighthouse and travel in the boat to the reef.
46. You will find a locket bearing a note supposedly from Fiona, who was the woman you met in the Haunted House. Travel back to the island and go to the House.
The Haunted House
47. Enter the house and find Fiona on the 2nd floor. Give her the locket and she tells how the man she loved, Valiant, was tricked by the forged note and died in the shipwreck. She says she threw a ring into the town fountain.
48. Pick up the scrapbook she drops to examine the old photos in it. Leave and go to the fountain on Main Street to look for the ring.
Main Street and the Cemetery
49. At the fountain, a seagull guards its nest on the fountain. Use the can of sardines to lure it away, and find the shiny ring in the top of the fountain. The engraving suggests a visit to the Engraver in the cemetery.
50. Go to the cemetery, and click the B to reach the B gate and talk to the Engraver. He suggests you look up the date August 18, 1929 in the newspaper archives.
51. Exit the cemetery (click on the H gate) and go to the Herald.
52. Downstairs, you can now use the microfiche viewer to look at old stories in the archives. Turn the right handle clockwise until it reaches 1929, then zoom in to read. Henry Flatbottom is the town magistrate, dedicating a memorial to his "friend" Valiant Lovejoy, who died with the sailors aboard the ship Mermaid when it hit the reef. You go back to investigate Lot A of the cemetery.
53. At lot A, go left to find a tomb unsealed. Push the lid off and climb down into the chamber below.
54. There is a complex maze of tunnels, which you can go through by watching for the pink flower petals that blow in from the correct door. Go up, up, right, up, left, left, down, left, down, down, left, up, left, up, and right to reach the ladder in the left side of the maze.
55. The tunnel exits through the stump outside the cemetery gate, which is hollow. Hide at the left until the Cemetery Specter approaches, and sneezes (?). Chase the Specter down through the stump, and to the right across lot A.
56. When you reach the gravestone at the upper right, the Specter is revealed to be the Magistrate, who has been bringing roses to the grave of...Fiona. (Yes, you were talking to a ghost in the Haunted House.) Rather than marrying the Magistrate, she remained faithful to her lost love, Valiant. The 4 ghosts (Fiona, the Thief, the Warden, and the Keeper) arrive to forgive the Magistrate for his crimes. The ghost of Valiant Lovejoy appears and he and Fiona are together at last. All of the ghosts disappear and the Magistrate gives you the Island Medallion.
1) The one disparity of the island (playing the prison before the lighthouse) should have been avoided. Apparently you play the lighthouse first, then the prison, and then when you finish the prison and go to shore, you are summoned back to the lighthouse and meet the Keeper. This eliminates the "go right back" shown above for the Lighthouse.
2) An odd glitch can occur at the Inn. Instead of explaining about the old woman ghost, the Inn owners will sometimes act as multiplayer avatars (Chat/ Battle).