This has been a series about change - in the attitudes of contemporary architects, in public awareness, in the ways they are shaping our future environment. There has been some optimism, but the last ten years of anxiety and argument have thrown up many questions and too few answers. The seminal buildings of our century are still those of the 20s and 30s, of the so-called Modern Movement. But the last decade has seen new adventures in architecture that may, once their effects have been assimilated, join the list of seminal buildings of the century. A look at MICHAEL graves's Humana building in Kentucky, ARATA ISOZAKI'S Museum of Contemporary Art in Los Angeles, ROGERS'S Lloyd's Insurance building in London, and FOSTER'S Hong Kong and Shanghai Bank. In Paris, eight vast projects are in the making, catering for the demands of the next century. Architects and writers 1. M. Pei , Richard Meier Richard Rogers Norman Foster Philip Johnson Ada Louise Huxtable and Kenneth Frampton offer their own definitions of the changing role of the architect, still complex and uncertain. For the doubts we all have about architecture reflect the doubts we have about our society. Narrator ANDREW SACHS