Help

Oliver remained standing in front of the desk, still trying not to stare. The light blue sweater hugged her figure too closely, and the short skirt left little to the imagination whenever she shifted in her chair. He cleared his throat and forced his attention back to the material.

“So the proton gradient,” he began carefully. “You said the energy from the electron transfers pumps protons into the intermembrane space, right? Creating that higher concentration outside the matrix?”

Isabella nodded and turned slightly toward the small whiteboard beside her desk. As she reached for the marker, the sleeve of her sweater rode up just enough to expose the inside of her left elbow.

A dark, irregular bruise marked the skin there — deep purple at the center, fading into yellow at the edges. It looked recent and painful.

Oliver’s eyes caught it immediately.

“Dr. Keller—” He stopped. “Are you okay? That looks like it hurts.”

Isabella followed his gaze and quickly tugged the sleeve back down.

“It’s nothing,” she said evenly. “Just bumped it on a cabinet. Happens.”

Oliver didn’t look away right away. His expression stayed concerned, not curious in a prying way, just quietly attentive.

“It doesn’t look like a regular bump,” he said, softer now. “I’ve gotten plenty of those from the lab. That one’s… different.”

“I’m fine,” she replied, a little too quickly. She set the marker down without writing anything and turned back to face him. “Really.”

An awkward silence settled for a moment. Oliver seemed to realize he had pushed too far and gave a small, apologetic nod, shifting his weight.

“Sorry. I didn’t mean to overstep.”

“You didn’t.” Isabella exhaled quietly and folded her hands on the desk. “About the proton gradient. You’re correct about the concentration difference. That potential energy is what drives ATP synthase when the protons flow back in. The diagrams on pages 214 and 215 in the textbook show it clearly if you want a visual.”

Oliver listened closely, but his eyes still flicked once more toward her covered elbow before he caught himself.

“Okay. Yeah. I’ll look those over tonight.” He hesitated, then added, “If I still don’t fully get it… would it be alright if I emailed you? I don’t want to take up more of your office hours.”

Isabella met his eyes. For a second she looked almost relieved that the conversation had moved back to something simple.

“You can always email me,” she said. “That’s what it’s for. Don’t hesitate if something isn’t clear.”

Oliver gave a small, polite smile. The flush that had been on his neck earlier had faded, replaced by something quieter and more sincere.

“Thanks, Dr. Keller. I appreciate it. Really.”

He lingered just a moment longer than necessary, as if deciding whether to say something else, then turned and left the office, closing the door softly behind him.Isabella sat still after he was gone. She pulled the sleeve up again and looked at the bruise for a long time before covering it once more. Outside the window, students moved between classes under the afternoon sun. For the first time in days, the silence in her office didn’t feel quite as heavy.