The air smells like wet gravel and something else Bob can't name. He hasn't moved in three minutes. His knees are starting to ache against the cold ground, but he won't shift until Petunia does. She's standing rigid at the edge of the yard — her massive black form a statue against the gray dawn. Her ears are cupped forward, her tail hangs straight down, her whole body aimed at the treeline like a compass needle. He came out because she whined at the back door. Not her usual “I need to go out” whine. A lower sound. A sound he'd never heard from her before. When he opened the door, she didn't bound out. She walked slowly, deliberately, down the steps, and stopped exactly where she's standing now. Bob follows her gaze. The pines are dark silhouettes against a sky that's just starting to lighten. Nothing moves. No birds. No wind. Just the faint hum of the power lines half a mile away and the distant sound of a truck shifting gears on the highway. “What is it, girl?” he whispers. Petunia doesn't look back at him. She never does when she's like this. He's learned that much. When she's tracking something real, she doesn't break focus for anyone. Minutes pass. The sky turns from gray to pale orange. Bob's hand is still on her head, feeling the warmth of her fur, the steady rhythm of her breathing. She's not scared. She's waiting. Guarding. Then he sees it. A flicker of light in the trees — brief, electric blue, gone before he can be sure it was there. Petunia's head drops a quarter inch. A signal. She saw it too. Bob stands up slowly, brushing dirt from his knees. “Okay,” he says quietly. “I believe you.” Petunia finally turns and looks at him. Her tail wags once. Then she turns back to the treeline and sits down, patient as stone. The sky keeps brightening, but whatever she's watching for isn't done yet. And Bob realizes — he's not going back inside until she does.