It's the original trio of Addie, Zade, and the specter of her grandmother's house that really pulls the story forward, but the sequel, 'Hunting Adeline', puts them through a brutal wringer. Honestly, Zade's whole vigilante crusade takes center stage in a way that borders on exhausting; his chapters felt less like a dark romance lead and more like a grim action anti-hero at times. Adeline's struggle with the aftermath felt more compelling to me, her attempts to rebuild a semblance of normalcy while being dragged back into that violent world.
They do introduce a couple of new faces on the periphery, like that sketchy journalist poking around and a few more of Zade's morally gray associates, but they never really develop into proper main characters. The core dynamic remains intensely, almost claustrophobically, focused on those two. The house itself still feels like a character, but its role shifts from a haunted space to more of a fortified refuge, which I found less interesting than the creepy atmosphere of the first book.