Impossible Dead

Witch stares at the half-human corpses dispassionately. “Then what are they?”
“Impossible.” Lizard’s laser scalpel slices carefully through the body. “The organs have been dead for a while. The machine parts are just… random. They don’t keep the body alive, and they wouldn't keep it moving around after death.”
“They moved pretty well five minutes ago.”
“Yes.” The scalpel cuts through the skull with gory ease. “The brain was as dead as the rest. No intelligence.”
“They didn't fight like they were stupid.”
“Yes. And they screamed.” Lizard stands, scalpel disappearing. “They screamed their rage as they died again.”