Which is most clearly a negative turning point for Pi in the last part of Life of Pi?

I would choose the end of part twoPi and Richard Parker come upon land in what turns out to be Mexico. Richard Parker goes immediately off into the jungle without any kind of goodbye or acknowledgment to Pi. Soon Pi is found by humans, but he weeps over Richard Parker’s desertion. This section also marks the betrayal by Richard Parker, a betrayal Pi can never forgive—not the killing of the Frenchman, but the act of leaving Pi without any indication of a goodbye. The resulting feeling of loss and sadness, rather than any excitement or relief at having finally returned to land, is what Pi emphasizes at the end of his story. The reader is thereby reminded that, although Pi has survived, he has lost all his family and everything he cared about, and now must face that loss within the human world.