The search bar blinked patiently. “Aspen HYSYS download free,” Marcus typed, then pressed Enter.

The screen flickered. For a split second, the flowsheet wasn’t empty. It showed a fully built process—a distillation column, two heat exchangers, a recycle loop. But the labels weren’t chemical streams. They were names. Human names. “Maria – Reboiler.” “Chen – Condenser.” “Omar – Reflux Drum.”

The interface loaded, but the colors were off. The process flowsheet background was a deep, bruised purple instead of the usual white. The component libraries were empty. Instead of “Water” and “Methane,” every dropdown showed a single entry: “Φ - Permission Required.”

But something was wrong.

He clicked on the simulation environment. A dialog box appeared, but the text was strange. It wasn’t a typical error message like “License Not Found.” It read: “You have reached Unit Operation #3. Do you wish to continue? Y/N” Marcus assumed it was a glitch. He clicked Yes.