The young star is about to scare film fans as the star of horror film The Woman in Black, and he admits there were quite a few things that frightened him as a child - but none more so than the big bang.
He says, "I was afraid of ghosts when I was a kid and afraid of the dark and monsters under the bed. When I was a kid and somebody first told me about a nuclear bomb I would live in fear of nuclear war for the next five years of my life."
Nowadays, his biggest fear is creepy crawlies: "I don’t love cockroaches."
And he admits he doesn't buy into ghost stories anymore - so all the weird things that happened on the set of his new chiller didn't keep him awake at night: "This film was made entirely by cynics. Strange things have happened but I don’t explain it with ghosts. It requires actually way more explanation for me than justifying a ghost doing something."