A week later, the results were posted. Aris had aced it.

Unlike his main textbook, which presented drugs as isolated molecules fighting receptors like abstract chess pieces, Rang and Dale unfolded the story of the human body. Aris scrolled through a chapter on hypertension. It didn’t just list ACE inhibitors; it explained the physiology of the renin-angiotensin system first. It painted a picture of the kidneys, the heart, and the blood vessels as a synchronized orchestra, and then showed how the drug acted as the conductor slowing the tempo.

"It’s about the bond," Aris said, leaning back. "Think of a competitive antagonist like a guy sitting in a seat at a concert. The real fan (the agonist) can come along and push him out if he brings enough force—higher concentration. But a non-competitive antagonist? He breaks the chair. It doesn’t matter how many fans show up; the seat is useless."

Mara stared at him. "Where did you get that analogy?"