1969/70. Peter Toms comes to Cambridge to study archaeology at Radnor College. The experience of his first year is like that of so many freshers - an eventful social life running in parallel with a demanding programme of study.

But developments in the wider world make their mark in Cambridge as well. The colonels' junta ruling Greece seeks to improve its image across Europe by PR campaigns, and this includes a "Greek Week" in Cambridge in February 1970. Student protests against the campaign reach boiling-point in the so-called "Garden House Riot". Among the students arrested and later put on trial is one of Toms' college friends.

At the end of the academic year, Michael Rubiner, Professor of Archaeology, arranges an excavation of the Iron Age hill-fort at Wooderidge, on Salisbury Plain. Deputy director of the dig is Dr Helmut Raabe, an archaeologist based at the University of Maiblingen in Germany. Toms volunteers to take part, along with ten other students.

It is Raabe who guides the team's efforts towards unearthing evidence of the hill-fort's original purpose. Raabe has a hidden interest in the much more recent history of the site, and its secret use by the military at the end of the Second World War. His ultimate allegiance is to his paymasters in the East German Ministry for State Security.

Past and present collide as the dig becomes a nightmare. Wooderidge's nickname - Madman's Hill - proves all too true. None of those involved in the excavation will escape its malign influence