"Dr. Mercer?" Catriona's voice carries through the wood. "Saw your light still on. Thought you might want tea."
I open the door to find the police chief holding a thermos and two cups. She's changed from her uniform into casual clothes, red hair loose around her shoulders, expression friendly but measuring.
"You look like you’ve hardly slept since you got here," she says, moving past me into the room without waiting for aninvitation. Her gaze sweeps across my equipment, lingering on the microscope and sample containers. "Making progress?"
"Depends on your definition." I accept the cup she pours, wrapping my hands around the warmth. "I have more questions than when I started."
"That's how it works on Skara." She settles against the table, cradling her own cup. "The island doesn't give up its secrets easily."
The words carry weight. I study her over the rim of my cup. "The autopsy reports show chemical burns from the algae and cellular dehydration that doesn't match standard drowning. And the algae itself has cellular structure I've never seen in natural populations."
"So you think it's not natural."
"I think someone is cultivating it, maintaining it, possibly harvesting it from deep-water sources." I gesture at the samples. "These concentrations don't occur in nature without carefully controlled conditions."
Catriona sets her cup down carefully. "There's someone on this island who knows the deep waters better than anyone else."
"Why didn't you mention this person when I was asking about local diving operations?"
A small smile crosses her face. "Because Finn Rowan doesn't talk to mainlanders. He doesn't trust outsiders. He doesn't engage with anyone unless he chooses to. But the deaths have him concerned, and I think he might be willing to share what he knows if you ask the right questions."
"Finn Rowan." The name means nothing to me. "What's his connection to the deep waters?"
"He knows them—the thermal vents, the trench systems." She stands, collecting the thermos. "I can take you to him, if you're interested."
Every instinct says this is relevant. He's someone local who understands deep-water ecosystems, someone who might explain the impossible data I've been collecting.
"When?"
"Now, if you want. He keeps strange hours." She pauses at the door. "Fair warning, Dr. Mercer. Finn isn't like the other islanders. He's not particularly friendly, and he won't appreciate being questioned. But if anyone can help you understand what's happening in these waters, it's him."
I save my notes and grab my jacket. Science waits for no one, and neither does a lead this promising.
Catriona navigates the dark village streets like she could walk them blind, setting a pace that has me working to keep up. Cold air bites at my cheeks. Salt spray coats my lips. The ocean's roar grows louder with each step, and my exhaustion makes the shadows seem to move and breathe.
The path narrows as we leave the village, winding along the cliff edge where waves drown out other sounds. Catriona leads me down a steep track that requires both hands and careful footing. The stone is slick with ocean spray, the darkness absolute except for the small torch she produces from her pocket. My legs burn. My lungs work harder than they should. Fatigue makes every handhold feel less certain.
"He lives in a cave?" I ask, breathing harder than I'd like.
"He prefers it. More privacy than the village offers." She stops at a narrow opening in the cliff face. "Finn? It's Catriona. I've brought Dr. Mercer. She has questions about the deep waters."
Silence answers. Then a voice emerges from the darkness, low and rough with an edge that raises the hair on the back of my neck.
"Send her in. Alone."
Catriona gives me a look that might be sympathy or warning. "I'll wait here."
I step into the cave.
The temperature drops immediately. The sound changes, ocean echoes bouncing off stone. My eyes adjust slowly, catching shapes and shadows, the suggestion of a larger space opening beyond the entrance.
The walls glow.
Bioluminescent algae traces the rock face in patterns too deliberate to be natural—not the random colonization I'd expect from marine organisms, but something that looks almost decorative. The light pulses with a rhythm that matches the distant surge of waves, creating shadows that breathe and shift. Blue-green luminescence reflects off the dark water of a pool that dominates the center of the space, the surface so still it mirrors the glowing walls perfectly, doubling the light. The cave shouldn't be this bright. Bioluminescence this intense, this concentrated, this controlled—my training has no framework for it.
The air tastes of salt and stone, but underneath runs something warmer. Musk and smoke, wild and male, the scent saturating the space like a territorial mark. It's everywhere—in the cool air I breathe, on the damp stone my hand touches, rising from the dark water that laps at the natural ledge. My lungs fill with it, and my body responds before my brain can categorize the input. Heat unfurls low in my belly, unwelcome and undeniable, a purely chemical reaction I can't logic away.
This is a lair. The word surfaces from some primitive part of my brain that recognizes predator spaces, places where apex creatures retreat to lick wounds and count kills. The pool connects to the ocean—I can hear the surge of water through submerged passages, feel the pressure changes as waves rollthrough the system. He swims in from the depths. He lives here in darkness and cold, surrounded by impossible light.
