Nathan faces a life-changing moment of truth — the operation to donate a kidney to beloved grandmother Chel. With only three days to go until the transplant procedure, Chel's need to put her affairs in order inspires Nathan to write letters to his family. However when it comes to writing to grandfather Tom, Nathan struggles to find the words — and resolves to visit him in prison against Dave's wishes. Ben reacts badly to Nathan's letter writing scheme — anxiety and concern for his brother manifesting as irritation. Melissa calls Ben on this behaviour, and Ben makes his peace with Nathan before the big operation. Meanwhile Carbo's "twitching" date with Solar Panel agent Amy proves to be a disaster. Undaunted he vows to continue the hunt for a wife.