Jerusalem’s Church of the Holy Sepulchre is considered the holiest site in Christianity, and is said to house both the place where Jesus was crucified and his tomb. As a result, various religious denominations have been engaged in centuries of debate and dispute about rights and rituals within this sacred space. It is a delicate balance that often threatens to tip over into open conflict. For generations, a Muslim family has been tasked with protecting the key to the church, opening the building every morning and locking it every night. Now, the key is to pass on to a new generation. This film dives deep into the secretive world of the Church of the Holy Sepulchre and its host city Jerusalem, and reveals just how thin the line between conflict and co-operation is in this world shared – and claimed – by Christians, Muslims and Jews.