Zhou Gu indeed developed a high fever during the night.
The Duchess urgently sent someone to invite Doctor Xu from the Imperial Medical Bureau.
Dr. Xu was mentally prepared. When he was dressing Zhou Gu's wound during the day, he noticed a significant depletion in his physical condition. Given the severity of his injury now, it wasn't improbable that he would develop a high fever that night. As expected, the fever started to show its symptoms even before nightfall.
Carrying his medical kit, he hastened to the Duke Residence.
Zhou Gu's fever surged violently. Doctor Xu prescribed a fever-reducing medicine. However, even after an hour, the fever hadn't subsided. Startled, Dr. Xu switched to another prescription and increased the dosage. However, after the second dose and another hour passed, the fever remained unabated.
Zhou Gu was already delirious, spouting gibberish that was indecipherable.