Star Wars, Hollywood's most successful film ever, was largely filmed in Britain. So was Superman. So was Alien. Making money-spinning box-office films for foreign companies has become a habit with the British film industry, but it enjoys very little of the profits. In Hollywood (USA) Michael Rodd investigates what brings American producers to film in Britain. In Elstree (UK) he meets Han Solo, C3PO, Luke Skywalker and the creators of Star Wars. As they work on the film that is trying to follow that £400-million success, The Risk Business discovers how big-time moviemakers are also reducing the chances that they will lose their shirts, in an industry where eight out of ten productions are flops. But what's in it for us? When the price of shooting in Britain forces the Americans back home, will we have a film industry left?

To most of us the only important property of sugar is its sweetness, but to the two huge companies which dominate Britain's sugar industry it means power, profit and jobs. Tate and Lyle dominated the British sugar scene until we joined the Common Market. Since then it has suffered a drastic reversal of fortunes, and power has shifted to home-grown beet sugar and the British Sugar Corporation. This year Tate and Lyle has grasped an opportunity to fight back, and the two are locked in a private battle to decide who is to dominate Britain's sugar in the future. Judith Hann and Kieran Prendi ville report on the fierce in-fighting and on some of the likely victims in this struggle.

According to one researcher ' You can invent three new devices for getting energy out of the sea before breakfast, and two more after lunch if you're awake enough'. But will they work? Britain, at the moment, leads the world with more than ten designs for harnessing wave power. Kieran Pren diville and Judith Hann talk to researchers up and down the country who believe their ideas stand a real chance of success. But the Department of Energy and the Central Electricity Generating Board seem dedicated to a nuclear future; so is alternative energy just a dream or could we one day be switching on electricity that can never run out? In the end it all comes down to money: to how much it will cost. We do not know whether wave energy will ever appear to be as cheap as nuclear energy, but it could simply be that we are doing our sums the wrong way.

The cheapest and apparently the safest way to set up in business on your own is to buy a franchise - the licence to operate one part of a chain of shops, service companies, plumbing businesses, or even hotels. The masterminds behind the operation have done the groundwork for you, developed the product, advertised it nationally, even assessed the chances of your operation making you the fortune you desire. In theory, all you have to supply is the blood, sweat, and a cheque for a few thousand pounds. But is it so simple? Michael Rodd meets the American millionaire who pioneered franchising in Britain, yet still works as a flight engineer for Pan Am. He meets some highly-satisfied franchisees ... but then discovers that dreams can melt away when the franchisor isn't doing his job properly. Even franchising can be a Risk Business, and it pays to know exactly what you are doing when you plunge your life's savings into someone else's business.

Two years ago, Sarah Harrison was an unknown housewife living near Royston with an attic full of unpublished manuscripts. But since then she's become the author of what her agent and publisher claim will be a massive best-seller. They are attempting to get the book into the shops by hyping it - a process on which the success of all mass-market books depends. Tonight's programme investigates just how close ' The Hype' can come to conning the booksellers and the public. Judith Hann and Sophy Robinson guide you through the world of schlock, bodice rippers, hot historicals and sheer adulterated commercial publishing!

The double-decker bus is as British an institution as fish and chips or cricket, and, as the Empire expanded, so did the market for these peculiarly British products. Today, the United Kingdom satisfies 90 per cent of the world's demand for double-decker buses. But, as the world energy crisis expands, Britain's supremacy in the market is under threat. At home, Government policy looks set to reduce demand for new double-deckers and whilst British manufacturers work out how to handle that crisis foreign manufacturers are gearing up to challenge us in the rest of the world. Confident that everyone needs more rather than fewer double-deckers, both the Swedes and the Germans are even developing plans to bring their double-deckers to Britain. Judith Hann and Michael Rodd investigate why Britain's new generation of super double-deckers face problems, report on the new tactics of our foreign competitors and meet the British bus operators who say they may have to buy foreign to ' gee up our own

Japanese companies are bursting out of their saturated home markets and are not only sending more and more goods to us, they're exporting their factories too. Over 200 Japanese businesses now have a base in Britain, and in some of the fields where they've set up, like zips and colour televisions, they show signs of dominating the market. Kieran Prendiville and Bill Brcckon discover that they're bringing with them some startling new ideas in the way they manage British workers. So how much can we learn from them? Or are whole industries in danger of being swamped by this Far Eastern invasion?

This autumn sees the launch of two cars vital to the survival of Britain's car industry. BL's long-awaited Metro is the first all-British volume car for a decade arriving at a time when two out of three cars sold here are imports, and when there are severe doubts that Britain can sustain its own car-making company, The new Ford Escort is the result of years of collaboration between Ford in Britain, Germany and the USA. This multi-national car will determine the fate not only of Ford's European companies, out also of its debt-ridden American car operation. As Michael Rodd reports, 1980 will be the turning-point in Britain s car industry, whilst Andrew Neil reflects the view from Detroit where today's American crisis could well spell trouble for Europe's small-car makers.