Perrin depicts the feat of an extraordinary old man who builds a cathedral with his bare hands. 92-year-old Justo Gallego isn't an architect or a builder, nor has he received any training in construction at all. He couldn't even complete his basic education due to the outbreak of the Spanish Civil War. Nevertheless, more than 40 years ago he decided to build a work he could offer to God and to this task he has since devoted his life. Bit by bit, almost on his own and using mainly recycled materials, he has erected a monumental cathedral in a field in Mejorada del Campo, Madrid. There are no blueprints or drawings or any official project. Everything is inside his head. He says he has taken his inspiration from books on cathedrals and castles, but, above all, from the Gospel. He also says he will continue working in it for as long as he lives. Perrin's beautiful photographs, wrapped in black, dive into the very soul of Justo Gallego's work, into its heartbeat, and allow the mystery of the place to unfold.