Dr. Brigita Gessner, a neuroscientist in Prague, experiences a disorienting sensation of drifting high above the city’s snowy rooftops, seeing landmarks like St. Vitus Cathedral and the Vltava River. She feels massless and bodiless but mentally alert, which makes her suspect she has died.

Rejecting the idea of an afterlife, Gessner clings to her medical understanding that consciousness is brain chemistry and that death is final. She reframes the experience as an out-of-body experience (OBE), a hallucination sometimes reported during resuscitation, and realizes that if this is an OBE, she must be critically close to death.

A sharp memory returns: Gessner’s physical body is strapped to a machine she designed. A clay-coated, hate-eyed figure stands over her, calling himself a woman’s “protector” and accusing Gessner of betrayal. He starts the machine, sending unbearable pain up Gessner’s arm, and demands that she tell him everything.

Terrified, Gessner answers his questions and reveals what she and her partners have created deep beneath Prague, a truth he calls an “underground house of horrors.” He turns the machine back on and leaves, dismissing Gessner’s pleas by claiming death is not the end and that he has “died many times.”

Gessner returns to the floating, soundless vantage above the city as a thunderclap and an unseen upward force pulls her higher. Knowing she cannot survive and desperate to warn the others, she understands it is too late: her life is ending.