I’m not going to claim that Stoker intended his original “first” chapter (later set aside & published later as “Dracula’s Guest”) to give us an “origin of Renfield” account. However, as the films NOSFERATU, the Lugosi DRACULA, and Coppola’s DRACULA all have Renfield as either Harker’s superior, stand-in, or predecessor, could the story now be retrofitted easily to serve as such?