The door he came through backed on to emptiness where there should have been a wall, and around him the water gently rippled, reflecting the clear blue of the sky above. Across from him was another island, with another barred door backing on to nothingness.
Between the doors was a solitary island, with a single tree, the branches moving gently in breeze.
He walked across to the island, with the water lapping at his feet. His reflection followed him, looking up at him from under the endless lake.
On the island he now stood, looking around, seeing nothing but water stretching to infinity.
He walked over to the other door, with the water lapping at his feet. His reflection did not follow him.
On the island stood a figure, cloaked in darkness, a reflection of his self.
They looked at each other. One garbed in green, one garbed in darkness.
They watched in silence, each waiting for the other to make the first move. One true, one dark.
He unsheathed his sword, and prepared to conquer himself.