From Foundation Stone to Cross Flower - Rediscovering the Cathedral. Ox carts, construction cranes, pulleys, builders, stonemasons, and all sorts of colorful activity around the construction site - Christoph Baum brings the creation of Cologne Cathedral to life in his illustrations with great attention to detail. These large-format key scenes of the cathedral's construction begin even before the laying of the foundation stone, during the time of the Roman colony, and extend into the present day. Former chief architect Barbara Schock-Werner and Johannes Schröer explain the illustrations and recount the grueling work of the craftsmen at the construction site, secret passages through which Archbishop Anno II once had to flee from angry citizens, a strangely sounding imperial bell, plans to establish a Zeppelin stop at the cathedral towers, and how the cathedral was rebuilt after its destruction.