Henry gets nabbed
Whatever they were, they were inhuman and horrifying. At least, though, they fell quickly to Henry's sword once he had grown accustomed to its lightness and speed. When more of the monsters began to pour into one of the side windows, Henry scrambled to defend that breach.
Something grabbed him from behind-- something inhumanly strong and fast. It threw him into one of the bedrooms and slammed the door shut and locked before he could react.