Julian frowned, looking toward the ceiling as if trying to see through the floorboards. “Between them? Nothing, really. It’s an interior partition wall. Well, wait. There’s a plumbing stack from the downstairs powder room that goes up through the attic, but that’s sealed PVC. And… the HVAC return.”
“The HVAC return,” I repeated.
“Yeah. The original house had gravity vents. When the contractors put in the high-efficiency heat pump system last year, they had to drop a dedicated secondary return duct down from the attic to balance the airflow between those two bedrooms. It’s behind the wall between their closets.” He hesitated, his brow furrowing. “Why? Did you see water damage?”
“No water damage,” I said. “Do you have access to the attic hatch?”
Clara lifted her head from the table, her gaze sharp, frantic with the hypersensitivity of an embattled mother. “What did you find?”
“I haven’t found anything yet, Mrs. Vance,” I said honestly. “Just an odor in the hallway. It’s localized to that central wall. It might be nothing. But with neurotoxins, what looks like ‘nothing’ to an adult nose can be catastrophic to an infant’s blood-brain barrier.”
