“Check these babies out,” Kate Raab muttered, peering into the high-powered Siemens microscope.

Tina O’Hearn, her lab partner, leaned over the scope. “Whoa!”

In the gleaming luminescence of the high-resolution lens, two brightly magnified cells sharpened into view. One was the lymphocyte, the defective white blood cell with a ring of hairy particles protruding from its membrane. The other cell was thinner, squiggle-shaped, and had a large white dot in the center.

“That’s the Alpha-boy,” Kate said, slowly adjusting the magnification. “We call them Tristan and Isolde. Packer’s name for them.” She picked up a tiny metal probe off the counter. “Now check this out…”

As Kate prodded, Tristan nudged its way toward the denser lymphocyte. The defective cell resisted, but the squiggle cell kept coming back, as if searching out a weakness in the lymphocyte’s membrane. As if attacking.

“Seems more like Nick and Jessica,” Tina giggled, bent over the lens.

“Watch.”

As if on cue, the squiggle cell seemed to probe the hairy borders of the white blood cell, until in front of their eyes the attacking membrane seemed to penetrate the border of its prey and they merged into a single, larger cell with a white dot in the center.

Tina looked up. “Ouch!”

“Love hurts, huh? That’s a progenitive stem-cell line,” Kate explained, looking up from the scope. “The white one’s a lymphoblast-what Packer calls the ‘killer leukocyte.’ It’s the pathogenic agent of leukemia. Next week, we see what happens in a plasma solution similar to the bloodstream. I get to record the results.”

“You do this all day?” Tina scrunched up her face.

Kate chuckled. Welcome to life in the petri dish. “All year.”