Just when Karen and Joe Eastman thought they had it all - the perfect marriage and the perfect family - they learn that their young son, Ben, has a terminal illness. The only cure is for them to have a 'designer baby' to provide him with a perfect match bone-marrow transplant. But in the process, a devastating family secret is revealed that not only jeopardises the one hope of their son having a future but also threatens to destroy their marriage...