The accent got lost somewhere along the way. I'm a little embarrassed about it. When I arrived in LA I assumed I'd be able to put on the American accent. It proved difficult so I had six months working with a dialect coach and it's become a habit.

In 2010 it was announced Henderson had been cast in Grey's Anatomy creator Shonda Rhime's new television series Off the Map wherein doctors travel to the end of the world to rediscover why they had initially wanted to become doctors. In 2006 Henderson won rave reviews in London's West End in a theatre production of Fool for Love with Juliette Lewis. In 2005 he starred opposite Indian actress Aishwarya Rai in the romantic film Bride & Prejudice and in the award-winning Little Fish starring Cate Blanchett.