VIDEO : Dunkirk Star Fionn Whitehead Talks Landing Breakout Role

The 20-year-old tells THR he didn't even know what he was auditioning for before landing his high-stakes debut role in Christopher Nolan's war epic. Fionn Whitehead had no idea what the part was. "All people knew was that there was a group of boys auditioning," says Fionn (pronounced "fin"). "We didn't know how many parts there were, how important the roles were. We didn't know anything.