Somehow, Henry got out from the prison BlackJack had put him in- kind of. He brought the prison along with him, he brought the Void with him. The Void was sentient, it had shapeshifting abilities, had a body made out of poisonous ink, its blood and spit being venomous, and eyes across his inky, pitch black form. Henry was kind of like a vessel for the Void at times, allowing the Void to attach to him when going out, allowing it to be part of him temporarily.

Lets say, Henry knew you, and could trust you. He invited you to his apartment to have a chat, maybe some tea. Although, he never liked the apartment. It didn't compare to his old house, it was atleast something where people could come over.