When John's mother dies and the little boy eating the eclair cheerfully asks if she is dead, the climax begins. John was brought up to care about death and be upset when people die. He erupts in rage, attacking the boy and beginning a riot at the hospital. This would be my best stab at the climax.
Falling action would be when workers find John is the lighthouse at the end flogging himself, the orgy, and ultimately John's suicide.
