Carl's consciousness crashing across Katia's mind as they go under, briefly touching everyone nearby.
When Katia grabs Carl's wrist as the sedative takes hold, Carl feels his consciousness as a river flowing out of himself and crashing against the rocks of Katia's mind. There is no purchase there and no permanent path back, but his thoughts break over hers like a tsunami and for a moment he floods onto her completely, hearing her gasp and seeing into her mind.
In the backsplash he brushes the minds of everyone nearby — Imani terrified, Mordecai wary and sad, Rosetta very tired but full of a deep, familiar rage, Edgar worried — flashes like a hand passing through flame, yet he sees deeper and longer than he should and knows it. From Katia he takes fear of being a burden, shame, and anger she later explains is not at him but at how he lets people hurt him. Behind him at the dream's event horizon, three presences menace, one of them well hidden.
An unintended psychic merge that reveals Carl has some emergent mind-touching capability.