4. Legally High

Recent years have seen a step-change in Britain's drug culture. Out go the 'old' illegal drugs - cocaine, heroin, speed - swept to one side by a younger generation who can get their hits not only more cheaply but also legally. The new drugs are legal to buy because they're sold as research chemicals and labelled 'not for human consumption'. This hard-hitting observational documentary - directed by triple BAFTA-award winner Dan Reed - takes a trip into a murky world where underground chemists invent new drugs faster than the government can legislate against them.