“Peaky Blinders: The Immortal Man” star Cillian Murphy

Cillian Murphy, an Oscar-winner for “Oppenheimer,” is back in a new film, “Peaky Blinders: The Immortal Man,” a follow-up to his hit TV series about a charismatic gangster who rules post-World War I Birmingham, England. The Irish actor talks with Seth Doane about the appeal of portraying complicated or tormented characters; taking his work “deadly seriously”; and trying to have a nose for great writing.