French performance artist Abraham Poincheval will trap himself inside a 12-tonne limestone boulder for a week starting Wednesday, and upon emerging, sit on a dozen eggs till they hatch, The Guardian reported. Poincheval’s performance piece, which he thinks of as “an inner journey to find out what the world is”, will be set in the Palais de Tokyo museum of contemporary art in Paris.

The first part of the performance is titled “Stone”. The rock has been fitted with a toilet and air vents, and Poincheval plans to survive on fruit, pureéd foods and water, Quartz reported. He will also be hooked up to a heart monitor and a phone, in case of emergencies. He has, he said, been preparing his body to live in the rock for months now. “The purpose is to feel the aging stone inside the rock.”

His second performance, titled “Egg” will begin on March 29. He estimates that it will take three to four weeks till the eggs hatch. For this, his preparations include a planning a special diet to maintain the right body temperature and additional care to ensure the eggs do not crack. The chicks that emerge will be sent off to live with his parents, he said.

This is not the first time Poincheval has undertaken unusual forms of confinement as part of his art. He has in the past lived inside bears, a giant plastic bottle and in an underground cubby hole.