“ Enid? ” Tempest looked around and saw the hand belonged to Enid Maddox.

Enid was dressed elegantly as always, in a pencil dress with a black-and-white houndstooth print so delicate that it appeared gray if you didn’t look closely.

“I’ve been there,” Enid said. “You should let him be.”

Tempest winced. “How much did you hear?”

“Only that he wants a bit of space. I’m sorry to have interrupted, though…”

“It’s fine. You’re right. I need to give him some space. Do you want to join me?”

Tempest looked at Enid more closely now. Even though she was dressed immaculately, her hair was unusually unkempt and she had dark circles under her eyes.

“You heard about Lucas Cruz,” Tempest said.

Enid nodded. “I came to find you as soon as I heard what happened last night. You weren’t at your house, but your grandmother suggested this as one of the places you might be.”

Tempest checked her phone but didn’t see any missed messages from Enid.

“I didn’t call ahead,” Enid said. “I… I wanted to tell you this in person.”

Tempest was suddenly aware that there were only a couple of other diners around. Enid couldn’t be about to admit she had a hand in Lucas’s death, could she?

The server arrived, and Enid ordered an iced tea. That put Tempest at ease. She couldn’t imagine that Enid would do so if she was about to confess to a nefarious deed.

“What did you want to talk about?” Tempest hid her expression behind her coffee.

“Is it true that Lucas Cruz’s death has some strange elements?”

“I don’t think I’m supposed to be talking about—”

“I’m not here for gossip. We need to talk about Harold Gray.”

“ Harold? ” That wasn’t what Tempest was expecting.

“I know it’s not possible.” Enid twisted a napkin between her fingers. “I mean, the rational part of my brain knows it’s not possible. But.”

“Enid. Are you trying to tell me Harold’s ghost killed Lucas?”

Enid gave Tempest a defiant stare. “You know me, Tempest. I’m not one for flights of fancy. But there are some things and—” She broke off from whatever she had been about to say and instead said, “I still don’t know why Harold asked me to oversee the library instead of Mrs. Hudson.”

“The two of them had a falling-out, didn’t they?”

Enid paused before answering, “But she’s a trained librarian, unlike me.”

“You love books and classic mysteries so much,” said Tempest, “that you figured out how to open a library devoted to your favorite genre. You hired the right people, and within a few years, you made it thrive beyond your wildest dreams. It’s no surprise that a friend and fellow classic mystery lover appointed you in charge of setting up his sister library.”

Enid gave an awkward shrug. “I got the sense that there was something left unsaid between Harold and Mrs. Hudson.”

“Romantically?”

“I don’t think so. She’s decades younger than he was. I know that doesn’t matter, but that wasn’t the sense I got from their relationship.”

“You mean the fact that she’d grown to hate him.”

Enid shook her head. “There was something more complicated going on.”

“But you don’t know what it was?”

Enid twisted the napkin even more tightly between her fingers. “I was thinking… maybe we could ask Harold. If he really is haunting that house, we could contact him to ask what’s really going on. That way we’d know for certain if he was involved.”

Tempest studied Enid Maddox. She was outwardly well put-together, and she always carried herself confidently, but she was incredibly nervous today. She wasn’t joking.

“A séance?” Tempest asked. “Sanjay isn’t a real medium, you know. When he does séances, they’re performances. And he’s sworn never to do one ever again. Not after what happened at Lavinia’s house.”

“I don’t know if that’s what I even meant.” Enid twisted the napkin so tightly that her knuckles were turning white. “Do you know why I love locked-room mysteries?”

“Because they’re pretty damn awesome?”

That got a small smile from Enid. “Because you get a ghost story with a rational ending . The whole premise of an impossible crime story is that it looks as if there could only be a supernatural explanation, but then you get a perfectly rational and satisfying explanation at the end.”

“You’re not in it for the fun of a page-turning mystery?”

Enid shrugged. “I like the puzzle, but that wasn’t the main appeal for me when I started reading mysteries. I was drawn to impossible crime mysteries because of what happened .”

Enid’s hands shook. As soon as she noticed, she abandoned her mangled napkin and hid her hands beneath the table.

The server dropped off Enid’s iced tea, giving Enid a moment to compose herself. She stirred a sugar packet into the tea and watched the liquid spiral.

“When I was a girl, just ten years old, the elderly woman living next to us died. It was a full week before anyone found her body.”

“How awful.”

“What’s even worse,” said Enid, “is that for that entire week, I saw her .”

“Oh, I’m so sorry, Enid. You saw her body from your bedroom window?”

Enid shook her head. “No. I mean I saw her walking around. At least that’s what I thought at the time. But when I learned what had happened, I knew it was her ghost I’d seen.”

Tempest blinked at Enid.

“I know you don’t believe me,” Enid said.

“You were a kid—”

“I was. And nobody believed me. They said it was my imagination. It wasn’t. But as soon as I discovered Ellery Queen, John Dickson Carr, and Agatha Christie as a preteen, they gave me the answers I desperately needed. I learned, then, that there were all sorts of ways that the impossible situation I saw could have happened. I was told that the house was locked up, but maybe a squatter had figured out how to get inside to take advantage of a warm house in the wintertime. Or maybe the police got the time of death wrong because of some trick with the temperature of the room. Or maybe she didn’t die of natural causes but was murdered and the killer was back to cover up their tracks. I was relieved.”

“Relieved that she could have been murdered?”

Enid laughed. “No. Relieved there were so many possible rational explanations to something that appeared impossible. But now?” Enid’s smile fell away. “Being inside that house, seeing a truly impossible crime in front of my eyes that first night when there was some sort of twisted game set in motion. And the next night another impossibility that ended in murder? It’s something Harold would have loved.”

“You think Harold Gray is a murderer?”

Enid gave a hopeless shrug. “You were there. I need to know… was it really impossible? Or can you give me the rational explanation?”

“We’ll figure out what happened,” Tempest assured her.

“So you can’t give me a rational explanation.”

“Not yet. But it can’t be impossible. It can’t be Harold Gray’s ghost.”

“Can’t it? Ivy told me you heard Harold’s voice.”

That’s why she was here. Ivy had shown up to work and already told Enid everything.

“We heard something that sounded like him. Maybe Cameron knows how to imitate his great-uncle’s voice. Maybe—”

Enid gasped. “You think Cameron —”

“I didn’t say that.” Tempest really needed to think before she spoke. Especially to someone thinking irrationally because of a childhood trauma. “I was just pointing out that there are numerous possibilities.”

“Such as?”

Tempest took a sip of the coffee from her warm mug, hoping it would give her time to figure out what to say. It didn’t.

“The police are working on it,” she said instead. “Detective Blackburn won’t let this murder go unsolved. There’s going to be a rational explanation.”

“I hope so,” said Enid. “I hope you’re right, but I don’t think you are. I should have trusted my gut all those years ago. I don’t know what happened to my neighbor who lived next to my childhood home, or in Harold Gray’s house, so be careful, Tempest.”

Enid was right about one thing. Whatever was going on in Gray House wasn’t a straightforward murder.