He finally looks at her, but his eyes show no sign of him recognizing anything odd about his behavior. Looks like yelling at him won't be enough to break this trance. There's no use trying to break the spell, either; Rita's technique needs a stationary target, and Childermass has no intention of stopping.

When he pulls his arm back, Rita stumbles forward with it. In the end, he's a grown man and she's a small girl; she simply doesn't have the physical strength to hold him back. That's not to say she's powerless, though. If tugging on him got him to look at her, maybe a good shock could do some good...

Rita releases one of her hands and swings it back, then tugs against his arm with the other to give herself some momentum as she balls it into a fist and throws a punch up at his face.