"I'm looking for my friend - Vivien - have you seen her?"

The Doctor encounters potty archaeologist Victoria Rumford who is on a quest to find out the secret of the stone circle of Boscombe Moor. She's heard that the stones are an integral part of an ancient weight loss programme and is keen to make a witty documentary about it.

But is the Professor's friend Vivien all she seems? Or is she really an intergalactic criminal on the run from sparkly justice machines housed above the Earth who will be accidentally released by the Doctor and put him on trial for his life as a result?

Will the Doctor outwit the justice machines?

Will Professor Rumford make her documentary or will she be forced to go back to aqua-aerobics in the west Midlands and that damn pool in Leamington Spa?

The Doctor is about to learn an important lesson about the importance of high quality dialogue but will he live to enjoy it?