Timothy Lanzone on the set.

*Travelling Salesman* is an unusual movie: despite almost every character being a mathematician there's not a mad person in sight. Moreover, the plot centres on one of the greatest unsolved problems in mathematics, does P = NP? Last month we were lucky enough to host the UK premiere of this movie, here at the Centre for Mathematical Sciences , the home of *Plus*. We spoke to Jonathan Oppenheim from University College London about the maths behind the movie and to the film's writer and director, Timothy Lanzone about creating drama from mathematics.

You can listen to these interviews in our podcast and read more about the P versus NP problem in this article.