What actor has starred in both Harry Potter and Regression?
Regression (film): Regression is a 2015 Canadian-Spanish-American psychological thriller mystery film directed, produced and written by Alejandro Amenábar. David Thewlis: David Thewlis (born David Wheeler; born 20 March 1963) is an English actor, director, screenwriter, and author. David Thewlis:  His most commercially successful role to date has been that of Remus Lupin in the "Harry Potter" film series.
i don't know