Lucy felt a huge sense of relief. This would all be over soon. The cops were on the way. They’d be here any minute. In fact, they might be here already, she thought, hearing a knock on the door.

Or not, she discovered, peering through the peephole and seeing a figure with a remarkably distorted face. She was puzzled at first, wondering if this was a person with a terrible injury, but she finally realized it was a man with a stocking over his face.

She was hitting REDIAL, calling Girard, when to her horror she saw the door open, restrained only by the security chain. She reached for the knob to pull it shut but was too late; the stocking man had inserted a pair of bolt cutters through the slim opening and had snapped the chain. It was only when the bolt cutters were withdrawn that Lucy saw her chance and pulled the door shut, yelling for Elizabeth.

Elizabeth took in the situation immediately and grabbed hold of the few inches of chain that remained, dangling from the door. She held on as tight as she could, and Lucy hung on to the knob, but the assailant was strong and had the advantage of leverage. Peering through the peephole, Lucy saw he’d placed his foot on the wall, beside the door, and was using it to brace himself.

Lucy’s hands were sweating. She felt the knob slipping from her grip in what she feared was a deadly tug-of-war. Elizabeth was also straining to hang on to the short piece of chain, her body pressed against Lucy’s.

“I can’t hold it much longer,” she whispered.

“Me, either,” said Lucy, who suddenly remembered her high school physics class, something about equal and opposite forces. “At the count of three, let go,” she whispered.

Elizabeth shook her head. “I’m scared.”

“It’s our only chance,” said Lucy. “Trust me.”

“Okay.”

Lucy whispered the count. “Un, deux, trois!” They let go simultaneously, and the door flew open, sending the assailant flying across the small hallway at the same time they heard the woo-wah of a police siren approaching. The guy ran for the stairs, and Lucy pulled the door shut, her chest heaving.

Once they were safely inside, she and Elizabeth fell into each other’s arms.

“That was good thinking, Mom,” said Elizabeth.

“I got an A in physics,” said Lucy, who was still breathing heavily.

“It’s broken,” said Elizabeth, who was examining the lock. “And the chain’s cut. I can’t lock the door. What am I going to do?”

It was suddenly quiet; the woo-wah had stopped, and they heard footsteps on the stairs. A moment later two uniformed flics were at the door.

“You’re breathless, madame?” asked one, emphasizing the password. He was young and good-looking in a rakish way, and Lucy thought he looked a bit like the young Jean-Paul Belmondo.