Sex is a simple word for a very complex set of desires. It cuts to the core of our passions, our wants, our emotions. But when it goes wrong, it can be the most painful thing of all. Professor Alice Roberts looks through 45 years of Horizon archive to see how science came to understand sex, strived to solve our problems with it, and even help us to do it better. Can science save the day when sex goes wrong?

In an eye-opening episode, reporter Ade Adepitan and director Andrew Carter travel to Kingston to investigate the growth of homophobic attacks in Jamaica and to meet the gay and transgender group who\\\'ve ended up living in a storm drain, where they suffer shocking violence, attacks and insults because of their sexuality.