I recall this being said by Mr. Del Toro in relation to Johann Kraus; the article was posted or a link was posted by Hellmistress in the Hellboy II spoiler forum. Being that Johann Kraus is an ectoplasmic entity, could he conceivably traverse the our world and the Afterlife at his leisure, correct? Perhaps Hellboy gets curious about his beginnings. With Johann's help, I could see Red being thrust into a situation similar to The Chained Coffin which could lead into The Island. Both are great explorations of Hellboy's birth, purpose, and future that I think would be fitting conclusions to Mr. Del Toro's trilogy.