Benedict Cumberbatch has a way to make The Courier even more interesting for viewers

In the new movie The Courier, Benedict Cumberbatch plays Greville Wynne, a salesman circuitously recruited to pass information back and forth between British intelligence and the Russian spy known as Ironbark. Not being a spy himself, Wynne—and Cumberbatch—faced a bit of a learning curve, though not always for reasons we see on the screen. As Cumberbatch tells The A.V. Club in the interview above, Wynne suffered from dyslexia so severe he was almost illiterate and battled classism in both his work and his marriage. It’s those little details that helped Cumberbatch really capture Wynne, ultimately helping him deliver a fuller performance than just what was on the page.

The Courier hits theaters March 19, and will arrive on VOD in April.