Hollywood has a not-so-mysterious way of casting who they want for roles in films and television shows with major IPs. There is usually a breadcrumb trail that you can trace back to a few previous projects that will help you understand why a choice was made for a particular actor.

The premium cabler is in talks with John Lithgow to play Albus Dumbledore, the headmaster of the Hogwarts School of Witchcraft and Wizardry. News of Lithgow’s potential involvement follows THR ‘s reporting that British actor Paapa Essiedu ( I May Destroy You) is in discussions to play Professor Severus Snape. HBO declined to comment.