Complex sentence: Ralph starts developing his suspicions about the heir to the throne, and this is confirmed when he gets Duncan to confess and learns that Willingham is another heir to the throne and had initially refused to accept the role.
Split into simpler sentences: Ralph starts developing his suspicions about the heir to the throne. His suspicions are confirmed when he gets Duncan to confess and learns that Willingham is another heir to the throne and had initially refused to accept the role.