Since becoming best of friends, Sean had indulged Zoe’s obsession with sleuthing and solving crimes. While he knew it was all a game, he always had a good time whenever they went off on “assignment.” She was Sherlock Holmes and he, Dr. Watson.

Sean defended Zoe when his other friends questioned his relationship. “I know she’s a little out there,” he’d say, “but we have such a good time. What’s the harm?” While he considered their activities just for fun, she took much of what they investigated seriously, making their excursions even more fun and exciting for him.

“Let’s go over the West Side Strangler case again,” said Zoe. “Six women have been murdered so far, always on the fifteenth of the month and always on the Upper West Side of Manhattan. It must mean the killer lives or works on the West Side.”

“How do we know it’s a he?”

“A female murderer might have gotten it over on one or two of the victims, but some of those women who died were really fit. Rosie Florio was a professional dancer and took kick-boxing. She would have been strong enough to fight off a woman. Plus, they were all strangled, which takes a tremendous amount of upper body strength. I definitely think it has to be a man. From what I can tell from the news reports, the police have nothing. They need our help, don’t you think?”

“Definitely. Let’s go over the facts,” said Sean, suddenly serious. “The first murder was on December 15th—Lisa Eng, mid-twenties, inside her apartment on West 95th Street.”

“Right,” said Zoe, still looking out the window.

“Next, Carly Faircloth, mid-thirties, on 104th Street in January, also strangled. Then, Nicole Barrett in February on West 96th Street, followed by Rosie Florio on West 97th in March.”

“Don’t you think it’s interesting that the pandemic and the lockdown hasn’t slowed our killer down. He stays right on schedule—the fifteenth of the month.”

“Good point,” said Sean. “Okay, the fifth killing in April was slightly different. Michelle Rothberg, was a little older than the others, in her thirties, and according to the police reports, she was temporarily disabled, having recently had foot surgery.”

“Right. They said on the news that she wasn’t supposed to be walking around. But, witnesses in the neighborhood said they saw her limping down her street the day she was killed,” said Zoe, still scanning the street below.

“Last but not least, victim number six, Katie Tierney on May 15th on West 100th,” said Sean. “The police believe all six women let the killer into their apartment because there was no forced entry. Why would a woman let anyone into their apartment when they know there’s a serial killer loose?”

“Maybe they all knew him?”