Sellers hesitated for just a moment, then spun me around and pushed me down the corridor at a run.

The wheel-chair had skidded to one side of the room and tilted over to its side. A bloodstained bandage was unwound and lying on the floor. Bertha was calmly sitting on Amelia Jasper’s shoulders, holding one leg in the grip of iron.

Amelia Jasper was kicking with the other leg, screaming and shouting for help.

Sellers shouted, “You can’t do this, Bertha. You can’t do it.”

“The hell I can’t,” Bertha said grimly. “I’ve done it. Look at the bullet hole.”

Sellers grabbed Bertha’s shoulders. “Let her up, Bertha. You can’t do that.”

Bertha said, “I tell you, I’ve done it.”

Sellers grabbed Bertha’s shoulders and tried to move her.

She gave him a push that threw him off balance, and he swung around crazily for a minute, trying to regain it.

In the doorway, Susie Irwin, the maid, stood grimly efficient, holding a blue-steel revolver. “Put your hands up, everybody,” she said.