A group of young people visit the hillfort of Maiden Castle in Dorset, England, and think themselves back in time. They realize that archaeology is all about building up a picture of what life was like in the past. The archaeologist at work explains the techniques of modern archaeology and what his team is actually doing at Maiden Castle. Reconstruction paintings based on real evidence help to show life in the Iron Age, as does a visit to an experimental farm which uses the farming 'technology' employed by people over two thousand years ago. The children work on the evidence on site and in the local museum in Dorchester. Through a series of 'dissolves' they are transformed into the Iron Age people who defended the fort and the Roman soldiers who stormed it, while archive film shows Sir Mortimer Wheeler giving a vivid analysis of the battle of AD 43, based on what he learned from his excavations.