An extraordinary event occurs at a rural pharmacy. Pharmacy manager Sychra discovers that one of the pharmacy staff has mixed peroxide into the ointment instead of distilled water. During the night shift, he immediately calls all employees to the workplace. It turns out that the defective medicine has already been dispensed to four sick children. Although it does not pose a health risk, it is a burden for the children. The search for the culprit focuses on Lída, a lab technician and honest worker who immediately admits to the mistake, saying she used an unlabeled bottle. However, it is clear that someone else was involved in replacing the distilled water with peroxide...