This is the incredible story of Trishna and Krishna, twin girls born joined at the head. Abandoned shortly after birth at an orphanage in Bangladesh, they had little chance of survival, until they were saved and taken to Australia by an aid worker. After two years battling for life, the twins are ready for a series of delicate operations, which will prepare them for the ultimate challenge: a marathon separation surgery that will allow them to live truly separate lives. Surgeons knew there was no guarantee of survival for either of the girls -- but without surgery there was no hope at all. With exclusive access, our cameras have been with Trishna and Krishna and their caregivers throughout their journey.