You’re not drinking it, I realized after watching de la Cruz for a moment. This was a man who knew exactly how he was perceived—and exactly how to manipulate that perception. He made eye contact with a nearby woman.

She smiled.

To you, everything is an algorithm. Everything can be predicted. I couldn’t pinpoint what precisely gave me that impression—the fit of his swimsuit? The attentiveness behind his eyes? You have a PhD in mathematics. What kind of professor plays professional poker on the side?

Before I could reason my way to any answers, Lia bumped into de la Cruz. He caught his drink an instant before he spilled it on her. Good reflexes.

Beside me, I could practically hear Dean gritting his teeth.

“She’ll be fine,” I murmured, even as I thought about our UNSUB, the Fibonacci sequence, the care with which the first two murders had been planned.

“She’s going to be fine,” Dean muttered. “I’m going to have a heart attack.”

“What did I say, Jonathan?” A sharp voice cut into my thoughts. To my left, a man with perfect hair and a face riddled with barely masked displeasure stalked over to a little boy of maybe seven or eight. Whatever the boy said to him in response, the man didn’t like it. He took another step toward the child.

Beside me, Michael’s entire body tensed. A moment later, he was so relaxed that I wondered if I’d imagined it. He climbed lazily to his feet, brushing a speck of invisible dust from his shirt as he began weaving his way closer to the man and the boy.

“Dean,” I said urgently.

Dean was already on his feet.

“I’ll keep an eye on Lia,” I told him. “Go.”

Michael settled at a table adjacent to the boy and his father. He smiled pleasantly, staring out at the pool, but I knew better than to think the positioning was coincidental. Michael had learned to read emotions as a defense mechanism against his seemingly perfect father’s volatile moods. Anger was the emotion that most set him on edge, but the kind of anger that hid behind masks, in the middle of seemingly perfect little families?

That wasn’t just a trigger. It was a ticking bomb.

Dean took a seat at the table Michael had claimed. Michael propped his feet up on a spare chair, like he hadn’t a care in the world.

True to my promise to Dean, I forced my attention back to Lia and the professor.

“You seem to be quite knowledgeable about the state of our investigation.”

It took me a moment to realize that the audio had clicked back on in my earpiece. Briggs’s voice was clear, but the reply was muffled. Angling my head down and letting my hair fall into my face, I adjusted the volume.

“—my business to know. The first girl died at my party, and Camille was a friend, of sorts. For a man in my position, it pays to keep track of one’s friends.”

I scanned the surrounding balconies. There, toward the top of the dome, I could make out three figures. Two of them were wearing suits. Sterling and Briggs.

I wasn’t the only one who’d noticed them. Across the pool, the professor had locked eyes on Wesley and the agents as well. You notice things, Professor. You pride yourself on it.

I caught Lia’s attention and held her gaze for a second. She said something to de la Cruz, then headed back toward me. In a fluid, choreographed motion, she pulled the ponytail holder from her hair, letting her jet-black tresses cascade down her back. As she took a seat beside me, she fit her own earpiece back into place.

“I don’t suppose you could be persuaded to part with the source of your knowledge on Camille’s case?” Agent Sterling asked. It was odd to be hearing her voice when I could only make out her silhouette on the balcony.

“Most likely not,” Wesley replied smoothly. “However, James would be happy to furnish you with my alibis for each of the past four evenings.”

Lia’s expression eloquently communicated her skepticism that Assistant James would be at all happy to assist the FBI in any way. I turned to try to get the boys’ attention, but neither Michael nor Dean was at the table where the two of them had been sitting a moment before.

Neither, I realized upon looking, were the young boy and his father.

As I scanned the crowd, Agent Sterling’s voice provided the sound track. “You’re an intelligent man,” she was telling Wesley, playing to his ego. “What do you think happened to Camille Holt?”

I finally saw Michael, leaning against the side of a camel-themed snack bar. A few feet away, the young boy and his father reached the front of the line. I looked for Dean and found him caught behind a massive crowd of forty-something women, trying to make his way through them to Michael.

“What do I think?” Wesley was saying over the audio feed. “I think that were I in your shoes, I’d be particularly interested in Tory Howard’s rather unique skill set.”

A few feet away from Michael, the young boy reached up for an ice-cream cone. He smiled up at his father. His father smiled back.

I breathed an internal sigh of relief. Dean finally made his way through the crowd and began to close in on Michael.

At that instant, two things happened. On the audio feed, Agent Briggs asked Thomas Wesley to clarify his comment about Tory’s skill set, and near the snack bar, the little boy stumbled and the ice cream fell from his cone and onto the ground.

The world fell into slow motion for me as the boy froze. The father made a grab for his son, his hand locking around the boy’s arm as he jerked him roughly to the side.