By the time Mordred returned to the palace, the officials were already frantic with impatience. He had been gone for three or four hours, far exceeding the previously agreed-upon two-hour limit.
If they had not known that Prince Mordred was extraordinarily powerful and not someone who could easily be harmed, they would likely have issued martial law and launched a citywide search.
Fortunately, everyone still retained their reason. With the crown prince overseeing the state, stability had to come first. If matters escalated to the point of deploying the Imperial Guard, it would only lower the crown prince's standing.
Though things had not yet reached that point, the palace guards and Imperial Guard had long since geared up and stood ready. Had Mordred returned even a moment later, the martial law order would likely have been issued for real.