Spoilers for The Mummy. Also - American Werewolf in London (Why haven’t you seen that yet, if that matters?)
You have been cursed by this ancient supernatural being. Your friend, who fell victim to it first and died in front of your eyes, now comes back from the dead several times, all messed up and decaying, following you through London to inform you that your only way to be free from the curse is to give in and die.
Look, I love. American Werewolf in London. It’s the best Werewolf movie and one of the greatest horror flicks ever, IMO. Shouldn’t you wait for your Wolfman movie to rip that one off, though?