You have to get the chicken and give it to the farmer that has all the bugs eating his crops.Use the chicken to get the blue light.
the bat
you get the chicken then give it to the man withe crops that the flies are infesting and the chicken will eat the flies and the man will give you a blue candle
You have to get the blue candle. Once you get that you have to read the writing with it.
you go to the left side of the island there is a old woman there and she gives you a blue candle after thet you go to the governers houce an use it on the note
The gravestones are in the cemetery to the right of the house. When you have all 4 treasures, and fueled the lantern in the basement, talk to the ghost cat and he will tell you to go to Betsy Blue's gravesite.
Once you have all 4 treasures, get fuel from the kerosene barrel in the basement and see the ghost cat, who will send you to the grave of Betsy Blue in the cemetery.
For a mummy costume, you can copy the one from the Haunted House game. The mummies at Nabooti Island are in the Sphinx at Giza. There are three challenges to defeat to recover the Blue Jewel. (see related questions)
Once you have all 4 treasures, and fuel the lantern, the ghost cat will tell you where to go, which is back to Betsy Blue's tomb in the graveyard. There should be a hole there that you can enter.
Once you have all 4 treasures, and fuel the lantern, the ghost cat will tell you where to go, which is back to Betsy Blue's tomb in the graveyard. There should be a hole there that you can enter.
If you have the chalice already, fuel the lantern with kerosene in the basement. Once you have all 4 treasures, the ghost cat will tell you where to go, which is back to Betsy Blue's tomb in the graveyard. There should be a hole there that you can enter.
Take it to the Governor's house to the right of the farm. The governor has a parchment that has partly faded. Use the blue candle to reveal the hidden part of the text.
He will give you one of his chickens, and you can give that chicken to an old person to the right to eat the bugs and pests in their garden. They are so grateful they give you a blue candle, which is all they have. Bring the blue candle to the old govenor's house and use it. It turns out, the secret document they are reading can only be read under blue light! Congratulations, you now can set off to play Skullduggery island.