The Roman Invasion through the mind of a Druid high priest

This is the story of a bricklayer. A master of his craft, he keeps its sacred teachings secret. For him a house is the dwelling place of a soul, and a house must be built in the right spirit or the soul inside it will suffer. The building of an arch is a ritual to obtain a right relation with the earth and a connection with the truth. The bricklayer recalls his previous life as a Druid priest. He talks about the creation of the sacred landscape of these islands; how even a simple stick lying on the ground would tell people the direction they needed to go in; how when people stared at the stars, they were staring at their own mind. The reader sees the world through the eyes of this great, magical being at the time of the Roman invasion, and learns how he tricked Julius Caesar and set in train the series of events that would lead to Caesar's assassination on the Ides of March. But as the bricklayer continues, he worries he is losing his ancient, sacred powers. The vision begins to fray at the edges as we learn how he has recently taken violent revenge on yobs who have mocked him. Is he really connected to a once living Druid priest, or is he gradually losing himself in his own fantasies?