I first saw Jamie Campbell Bower in "Sweeney Todd". However, I arrived late to that movie for some reason. When I walked in to the cinema, he was singing "Joanna", and I was without context. I thought he might have been a younger version of Todd in a flashback to the barber's first meeting with his wife or something. This did not turn out to be the case. He was a friend of Depp's character instead of an earlier incarnation.
But I just saw Depp in "Fantastic Beasts", and now he's playing an older version of a character first brought to screen by Jamie Bower. It took eight years and a completely separate universe, but my poorly informed guess from that initial viewing of "The Demon Barber of Fleet Street" turned out to be right.