Ben Lewis returns for a new series travelling the world in search of contemporary art. He begins by looking at the work of controversial Belgian artist Wim Delvoye, whose work includes Cloaca, a machine based on the human digestive system. Delvoye is now tattooing pictures onto pigs - so the presenter decides to see how much a similar mural etched on his own back would fetch.

Ben Lewis looks at the work of controversial Spanish artist Santiago Sierra, who has recreated his downbeat view of the globalised economy and corruption in the art world by paying drug users to tattoo a line across their backs and filling a German museum with mud. Ben follows Sierra across the world from Hanover to Seoul to Dubai.

Sophie Calle is the Grand Dame of French contemporary art. Her famous works of art usually involve following a set of rules or a procedure – following a stranger to Venice; obeying a set of instructions from writer Paul Auster; or working as a hotel maid. Her art combines romantic autobiography and detached conceptualism. She gives Ben permission to make a film about her on one condition: he has to think up a ritual or set of rules for her to follow, similar to the rules which govern her works of art. Ben visits gallerists and theorists to take advice on what to suggest to her. He submits idea after idea. She rejects one after the other. Finally, in a final encounter with the artist, Ben realises that this ritual of rejection is the set of rules he wanted Sophie to follow.