It is the final day of the experiment, and the last chance for the volunteers to achieve their goals. In one final goodbye to 1975, a dinner party will be a chance to test how far each of them has come, and to see whether they really have turned back time. Undergoing the tests once again, what will the science say?In an emotional closing episode, each of the volunteers must say goodbye to 1975, and will discover whether they've really managed to turn back the clock. We'll see how their lives have changed since the end of the experiment - has it given them a new lease of life, or are they back to being just another old person in 2010 Britain?