"I tell you again, Kaitlyn. Please note the dosage in each vial." Gretchen's sharp tone and German accent could sometimes scratch its way into Kaitlyn's mind.

"Yep, 20 milligrams in this one, 25 in this one, and 30 in this one." She blinks her eyes beneath her safety glasses. "You think we've done enough for one night? Don't you ever feel how tired our body gets?"

Gretchen glares over at her. "Ja, I do. But are getting close to a good result here."

Kaitlyn lets out of soft sigh. "If a good result is falling asleep at the table, I suppose."