I do know in the 1960s comics, Martian Manhunter took on the form of a black man - that could have been influenced by the political climate back then.

If Mars formed life, then life on Earth could have been seeded by life on Mars, making every life form on Earth descended from Martians.

I've been acting for 27 years, and anonymity has always been a part of what I do. Of course you get recognised every now and again, but 'Homeland' pushed me into a completely different strata, and that took me by surprise.

I used to read comics as a kid, and now I'm reading them for research. It's great fun. It's not bad homework.

Back in 2005, the Anthony Nolan Trust could have asked me just to speak out about the lack of ethnic minority donors on the bone marrow register, but that would have meant nothing if I wasn't prepared to join up myself.

Working with Olivia Colman has probably been the highlight of my career so far.