This is a shocking incident that happened when an anti-Christian man stabbed the Blessed Sacrament in Paris.

During the 13th century, in Paris, France, there lived a man who despised the Catholic Church. He held an annoying hatred toward the Church and this anger led him to lash out. Eventually, he acquired a consecrated host to fulfill his devious ends.
He first of all, took the consecrated host and first stabbed it with a knife.
Instantly, a stream of blood flowed from the consecrated host. And this frightened the man, cause he never expected anything to happen. With fear, he quickly threw the host into the fire, with hope that he could get rid of the strange host.
Miraculously, the host then floated above the fire.
With desperation, the man grabbed the host and threw it in a boiling water. As he thought the host was gone for good, just then the host rose out of the water again and immediately took the form of a crucifix.
As he became greatly troubled at what he witnessed, he went and entrusted the host to a parishioner, who then brought the consecrated host back to the parish priest.
At the initial time, the miraculous host was enshrined in the church of St. Jean-en–Grève, but was later lost during the French Revolution.
So, a chapel was built at the house of the man who stole the Blessed Sacrament and where the desecration took place, and the place is now known as the Cloître et église des Billettes.
However, the miracle brought many to a strong belief in the Real Presence of Jesus in the Eucharist.