"I am the King! I don't need you to tell me what to do!"
King Uther was never a man who liked taking advice; frankly, he was stubborn and pigheaded. That's a terrible trait, but it wasn't uncommon for rulers in feudal societies. The key thing was, he was the boss, so even if he was being stubborn, no one dared to say anything.
At least, not Gaius.
"Of course, Your Majesty, the decision is entirely yours."
King Uther stared intently at Gaius.
"You swore you would never reveal the secret of Arthur's birth. I'm warning you, do not break your oath."
"Very well, sire," Gaius said with disappointment.
"Alright, Gaius. That's enough. You should go home. I'll talk to Uther properly. Get some rest; things haven't reached that point yet." Don't let King Uther's perpetually stern and emotionless expression fool you; he's actually a very emotional person. When he gets angry, he often does things he regrets later. Kay didn't want the decades-long friendship between Uther and Gaius to be damaged, so he quickly stepped in, urging Gaius to leave.
Gaius glanced at King Uther, who was still glaring at him, and nodded reluctantly.
"Fine, I'm going now. Remember not to get the wound wet for the next couple of days, and it should heal quickly." With that, Gaius packed up his medicine bag and turned to leave the King's chambers.
Once Gaius was gone, King Uther's angry expression vanished, replaced by a look of exhaustion as he sank into a chair, appearing utterly drained.
Kay didn't speak to Uther immediately. Instead, he picked up the flagon on the table, poured himself a drink, and wet his throat.
King Uther remained silent, too, constantly rubbing his face, trying to calm himself down.
After about ten minutes, Kay finally spoke.
"I think Gaius is right, Uther. Arthur should know some of the truth. You can't keep treating him like a child." Kay actually agreed with Gaius, but Uther had been so worked up earlier. If he had added fuel to the fire, given Uther's difficult temper, the conversation could have ended badly. That was totally unnecessary, which is why Kay waited for Uther to cool down before voicing his true thoughts.
King Uther looked up at Kay in surprise. He couldn't believe that even his most trusted surrogate son was against him.
"Why are you saying this too, Kay? Others might not understand the consequences of the truth coming out, but surely you do? If people find out the secret of Arthur's birth, everything I've done over the past twenty years will become a laughingstock! The entire kingdom of Camelot will be on shaky ground!"
Don't think this is a small matter. On the contrary, it's huge—so huge that King Uther would rather die than let the secret out. For the past two decades, Uther's primary mission has been to eradicate magic. To that end, he hasn't hesitated to kill countless innocent people.
For example, if a sorcerer was discovered in an inn, the entire place—from the owner to the staff and the guests—would be arrested and executed! Or, if a family was discovered to have a sorcerer among them, the neighbors on both sides could also be arrested, because living with a sorcerer for so long without reporting it counts as complicity!
In short, under Uther's iron rule, there have been far too many wrongful convictions and executions. However, given the genuine harm magic had caused, the people were forced to endure it. Uther, in that sense, held the moral high ground.
But if the secret of Arthur's birth were to spread, everything would change.
People wouldn't care what King Uther was thinking back then. They would simply and bluntly believe: King Uther, you've always been ruthless in killing citizens connected to magic—guilty or not—but why are you making an exception for your own son? Your son was also created by magic! He should be executed!
If that happened, Uther's previous moral authority would be completely destroyed!
And that's just one aspect. People in those days didn't have the power they do now. If King Uther really threw all scruples aside and used his army to suppress the people, the common folk wouldn't have much recourse—he is a tyrant, after all.
But there's one group that wouldn't be so easy to pacify: the entire noble class.
The reason the nobles of Camelot initially rallied behind Uther to wage war on magic was that they believed Uther's words—that magic was threatening their own rule over Camelot!
But now, they would suddenly discover that Arthur was conceived using magic! How would they react? The more moderate ones would just think Uther was being hypocritical, but the truly cynical ones would start worrying about what happens when Arthur takes the throne.
Strictly speaking, Arthur would be associated with the sorcerers. When he becomes King, what if he decides to avenge his "freak" friends?
There is also a critically important factor: power.
Once the legitimacy of Arthur's claim to the throne is undermined, he loses his right to inherit the crown. For opportunists, this would be a huge opportunity. More seriously, it would make many nobles who were previously loyal start to waver.
In summary, this matter has enormous implications—big enough that the Pendragon family could lose control of Camelot!
Under these circumstances, there's no way King Uther would agree!
Of course, that's still not the most important thing. Uther has been a strongman his whole life; all of that other stuff is minor. He'd just have to fight another war, which isn't a big deal for him. He faced down countless people who were terrified of going to war against the mysterious sorcerers and magical creatures, but he pushed through anyway. That level of boldness isn't his concern.
What truly gives him pause is Arthur.
If Arthur learns the truth of what happened all those years ago, what will he think? How will he look at his own father?
And honestly, some things are better left uninvestigated; the more you dig, the more trouble you find!
If Arthur's secret is exposed, it could lead to many other things being unearthed, which would inevitably involve another person: Morgana.
Morgana is the harder problem.
No matter what, Uther at least has an excuse he can try to use to explain the past to Arthur.
But Morgana?
Here's the spoiler on Morgana's real background:
As mentioned before, Morgana is Uther's biological daughter. But few know who her mother was. Simply put, Morgana's mother was Uther's lover. They conceived Morgana before Uther married Queen Igraine. The man Morgana grew up believing was her father was essentially just a beard...
But that's not the critical part. The critical part is that Morgana's mother was a sorceress...
...and she was killed by King Uther's own hand...
This is incredibly tricky. If Morgana finds out that Uther killed her magical mother and constantly concealed the fact that he was her real father, making her feel like an adopted, dependent guest for years, all just to maintain his reputation as King and out of spite—
If all these facts came out, Morgana's fury would be completely justified, even if she wanted to tear Uther limb from limb.
The beginning of all this was Arthur's birth. That's why King Uther absolutely cannot, and dare not, let this secret get out. Otherwise, his entire family could be destroyed.