Ethan's Soul Sense was stretched to its limit, covering an area far larger than he usually dared. He suspected someone nearby was controlling the black mist.
It had finally clicked where he'd seen it before—back when they were returning from Ravenwood, after the ambush. The woman they'd captured, the one without a tongue, had exploded, and something had shot out of her head, trailing the same black mist.
At the time, Ethan had only caught a fleeting glimpse of it. The thing had moved too fast, and by the time he'd expanded his Soul Sense to track it, all he'd seen was a faint tail disappearing at the edge of his range.
It had been a split-second impression, barely enough to register, which was why he hadn't connected it until now.
On the way back from Ravenwood, Ethan and Victor had discussed the woman and the two other bodies that had vanished. They'd theorized that all of them were puppets, controlled by whatever had escaped from the woman's head.