"This is the TaskMaker's prison. No tricks, no monsters, just a decision. The greatest prisoner is held upstairs." - In-game description
The Island Prison is the location of the last task, and can only be visited after completing the prior 9 tasks. It is a very simple dungeon, featuring a force field cage around the Prisoner that is unlocked when you approach.
---Island Prison in Tomb of the Taskmaker---
"This is a former prison. Years ago you have the last prisoner freedom, and now in return he’s given freedom to the prison. (I hope you brought a torch.)" - In-game description
Angel - This map's angel is named Marella and she can be found by climbing a ladder located behind a passwall in the Northeast corner of the upper level.
Instead of a prisoner, the center of the upper level has a Freedom Tree which provides unlimited Freedom Leaves.