Dr Alice Roberts follows an entire year of British archaeology, joining up the results of digs and investigations the length of the country. The results are astonishing and sometimes disturbing. This episode concentrates on Roman Britannia, where finds include the thickening mystery of 97 baby skeletons found by the Thames, a newly discovered town in rural Devon that turns history on its head, and a Roman cult figure buried for 1700 years beneath a fort.

In this week's episode, Dr Alice Roberts travels back to the Viking Age in Britain and visits excavations that are revealing a different side to these seafaring pirates from Scandinavia. She looks for signs of the earliest Viking settlers in the Outer Hebrides, and in Orkney - where Viking dominance outlasted anywhere else in Britain - she visits the excavation of a Viking chief's citadel and finds evidence of their way-of-life. There's an extraordinary collection of silver and gold that demonstrates the furthest reaches of the Vikings' trading empire and excavations in York - famously the capital of Viking England. This episode also includes a fresh look at some of our most celebrated Viking finds, such as the fantastic Lewis Chessmen, which are currently the subject of major new research.

Dr Alice Roberts travels back to the Ages of Bronze and Iron to discover what kind of a place Britain was before the Romans invaded. With no written history, only archaeology can provide the clues. Alice uncovers a world that is complex, sophisticated and pretty strange. She examines the two Hebridean Bronze Age skeletons known as the Cladh Hallan mummies. Not only do they appear to have been mummified, new analysis has revealed they are made up of a jigsaw of different people. What did our ancestors use the mummies for? And are there more British mummies out there? In Norfolk, Alice gets her hands dirty helping to pull up timber from a huge prehistoric monument that has been hidden in mud for at least 2,000 years. And she visits the famous Roman town of Silchester, near Reading, where archaeologists are digging below the Roman layers to reveal the Iron Age settlement that lies beneath, uncovering evidence for a sophisticated pre-Roman lifestyle. Alice also examines the evidence that suggests Silchester could be the place where two British chiefs took a stand against the Romans.

In the final episode of the series, Dr Alice Roberts goes in search of our elusive Stone Age ancestors. Along the way she visits the Channel island of Jersey where she meets a team of archaeologists hoping to shed new light on the much-maligned Neanderthals, and embarks on a kayak survey of the coastline looking for undiscovered sites hidden in the cliffs. At the Natural history museum Alice comes face to face with the dark side of our Ice Age ancestors lives - she sees evidence of cannibalism and the ritual use of human skulls. And she meets a team who are hoping to unlock the secrets of Stonehenge, not on Salisbury plain, but in the remote Preseli Hills of Wales.