Ellie's jaws dropped and her eyes stretched when she saw what happened to Mrs. Casey after he clicked his fingers.
She wanted to go help the woman, but a stronger voice was telling her to run. And that stronger voice won in the end when she heard Storm's voice.
Noticing that Mrs. Casey's chest was still rising and falling, Ellie turned toward the door, unlocked it, and took off without looking back.
Storm watched her go, amusement flashing in his eyes as if he was enjoying her distress. He didn't pursue, and neither did he make any effort to stop her.
As soon as she fled out of the house, he moved his gaze to Mrs. Casey. She was old, which means she was part of the generation that wiped out the vampires. He had great hate for anyone in that category, and wouldn't hesitate to end their lives, irrespective of whether they actively participated or not.