He nodded in understanding, then turned his head away, seemingly studying the passing throng for several moments. “I didn’t mind,” he said quite casually.

This time Sarah was dumbfounded. “Malloy, are you flirting with me?” she demanded, not at all displeased.

When he turned back to her, his expression was bland. “I thought you were flirting with me.”

Had she been? She thought back to her behavior throughout the day and realized she hadn’t been acting at all like herself, at least not the way she usually acted with Malloy. And he hadn’t been acting at all like himself, either, if the truth were told. They’d both been almost playful and slightly adventurous and much more informal than they had ever been in each other’s company.

“It’s this place, isn’t it?” she realized. “Here a person can break all the rules of propriety and not suffer any consequences!”

Malloy frowned, but she was too busy thinking aloud to notice.

“In the city, strangers don’t speak to each other, but here they offer advice as if they were dear friends. In the city, a man wouldn’t dare even tip his hat to a woman he didn’t know, but here he can introduce himself to a girl he’s never seen before, treat her to rides and buy her food and even kiss her in the darkness of the tunnels.”

Malloy was still frowning, but not in disapproval. He was thinking, too. “You’re right. People don’t act like themselves here,” he said. “No one knows them, so they don’t have to worry about what anyone else will think of them.”

“Which is why young people come here, so they can meet new people and have fun and their families won’t know what they’re doing. A girl can be forward and flirt and do things she wouldn’t dream of doing in her neighborhood where anyone might see her and ruin her reputation. Even going to the dance halls, a girl has to be a little careful because word might get back to her family, but not about what happens on Coney Island.”

“And men like your friend Dirk come out here to prey on those girls,” Malloy reminded her.

“Men of all kinds prey on them,” Sarah corrected him. She looked at the crowd passing down the midway before them, hundreds of people of every size and shape and age and status in life. Any one of them might have met Gerda Reinhard and treated her and tempted her and lured her to a dark corner and beaten the life out of her. “It’s hopeless, isn’t it?” she asked in despair.

“Finding the killer, you mean?”

She nodded glumly.

He sighed and watched the crowd with unseeing eyes while he considered. “If it was just one girl, then yes, it would be impossible.”

“But it wasn’t just one girl, was it?” How could she have forgotten? “There were three others! I found out their names from Gerda’s friends. I was going to tell you today, but in all the excitement, I forgot!”

He didn’t look at her. “They were Eva Bower, Luisa Isenberg, and Fredrika Lutz.”

“That’s right!” Sarah’s surprise quickly became anger. “You knew all along! You were just playing with me!”

“Don’t be a fool. I would’ve told you if I did.”

She supposed this was true, although she really had no way of knowing for sure. “Well, then, if you didn’t know their names before, how do you know them now?”

“I know Eva’s name because I worked on her case. She was the first one, as near as I can figure, which is why nobody thought it was anything out of the ordinary. Just another girl who took up with the wrong man and got beaten to death for her mistake.”

“You didn’t investigate?” Sarah was outraged.

Malloy just gave her one of his long-suffering looks. “She was just like this Gerda. She’d known dozens of men, and the ones we could find all had alibis. Nobody saw it, nobody knew anything, nobody cared.”

“But what about the others! Why didn’t you start questioning their friends to find out what men they all knew in common?”

“I didn’t know about the others until you told me the other day, remember?”

“But you know their names now!”

“Only because you told me other girls had been killed. I started asking around, and that’s when I found out about the other two cases. Two different detectives had them, and they didn’t know about any of the others, either.”

“How could this happen? Don’t policemen talk to each other?” Sarah was incredulous.

Malloy rubbed the bridge of his nose, as if he were getting a headache. “We talk to each other about important cases.”

“And the deaths of four girls isn’t important?” Sarah cried, but she didn’t need Malloy’s pitying look to remind her that no, these deaths weren’t very important in the grand scheme of things. No one outside their families cared about them, and none of their families had the money or connections necessary to ensure a thorough investigation. Even with all the resources money could buy at their disposal, the police were unlikely to solve any single one of these murders, simply because the pool of suspects was so very large.

But now Sarah saw a way to surmount all these difficulties. “The deaths of four girls is important if we can prove they were all killed by the same man, especially since he’s likely to kill again.”

“We don’t know the murders were committed by one man,” Malloy pointed out reasonably.

This time Sarah was the one giving the pitying look. “Oh, Malloy, I thought we already settled that. All the girls had been to a dance hall, and they were all killed the same way in the same neighborhood. How many men do you think are skulking around the city beating young women to death?”

“More than you’d like to imagine, I’m sure,” Malloy said. “And even if one man did kill all these girls, we don’t have any reason to think he’ll kill again.”

“How can you say that? He’s gotten away with it four times! He must think he’s invincible by now. If anything, he’ll start to kill more often!”

“What makes you such an expert on the criminal mind, Mrs. Brandt?” he asked sourly.

Sarah couldn’t resist. “All the training I’ve received from a very wise police detective.”

Malloy’s expression was priceless, but Sarah didn’t gloat. She merely smiled serenely.

Malloy finally found his tongue. “Do you feel up to walking back to the trolley station now? I’ve had enough of this place.”

“So have I,” Sarah agreed. “On the way back to the city, we can discuss how we’re going to proceed with our investigation.”

SARAH WAS ACTUALLY quite surprised that Malloy had agreed to allow her to help investigate the murders. She’d only been teasing him when she suggested they work out a system, but he had been willing-if not eager-for her to assist him. Apparently, the investigation into the murders of all the other girls had been abandoned just as Malloy had abandoned his, and for the same reasons. Sarah suspected that Malloy felt a bit guilty for not trying harder to solve the case that had been his originally, even though they both agreed the task had been hopeless with only one victim. Now, of course, they had a way of narrowing down the list of suspects.

Sarah had planned to begin with Gerda’s sister first thing the next day, but an early morning call delayed her. By the time she’d brought a healthy baby boy safely into the world, it was late in the afternoon. Men were returning to their homes carrying their now empty lunch pails, and the smells of thousands of suppers being prepared filled the hot, summer air as thunderclouds gathered overhead. At least a storm might break the oppressive heat.

Sarah hated to intrude on the Otto family at this time of day, and she certainly didn’t want to encounter Lars Otto again, but she also didn’t want to lose any more time in her quest to find Gerda’s killer. Maybe she could catch Agnes before her husband came home from work.

She climbed the dark stairs to the Ottos’ flat, the heat from dozens of cooking stoves turning the stairwell into a giant oven. The two older Otto children were playing on the landing, the boy entertaining the girl as best he could, probably trying to keep her out of their mother’s way. Young as he was, he could understand that his mother didn’t need any distractions just now.