When he woke up from having been possessed by the goblin, Gaius remembered nothing about what had happened. He remembered helping Merlin try to capture the creature, and it turning into a glowing mote, but there was nothing else until the boy called him an old goat.
Gwen told him about the farting, swindling, and donkey ears. Merlin explained the drinking, gold licking, and a few other things. Uther, Arthur, Sir Leon, and a number of the townsfolk filled him in on a few things as well, but no one told him that he was the one that accused Merlin of sorcery. That he learned himself a few days later.
Gaius had been incredibly busy since the goblin ordeal. He had to catch up on his rounds, return all the money the creature had extorted, and apologise to everyone who the beast had come in contact with. For the next two days, he was so tired that he would sleep deeply and soundly, without any dreams.
Today had been the first day that fell into his usual routine, so he hadn't been overly tired when he had retired for the night, and that was when all the memories came to him. He got to observe everything the goblin had done as him: hear his own voice taunt Morgana,
"I can see deep into your heart, and it's cold. Cold as stone. You play at being Uther's loving ward. You play it so well you fool him, but you don't fool me. You would see Uther dead and Camelot destroyed."
swindle the poor villagers,
"A broken rib that's become infected with the most severe and terrifying infection that can only be treated by this remedy. Alas, it's very expensive."
"Oh, we do not have any money to spare."
"In that case, your husband will die, and you'll spend the rest of your life in poverty and misery before dying a lonely, cold death, which is no less than you deserve."
arm wrestle and drink the night away,
"Shall we arm wrestle, or do you require a moment to recover what little strength you have?"
cast spells on Gwen, Uther, Morgana, and a good number of knights. And worst of all, he remembered everything "he" had said to Merlin.
The harsh words,
"You let it escape you stupid boy! Now you just stand there like a sack of potatoes. Go after it! Go! Shoo! Shoo!"
The threats,
"I can hurt you… Whereas, you cannot hurt me without hurting Gaius."
And then the accusations of sorcery.
"I found this in your room. It's a book of spells and enchantments."
"I fear that magic has corrupted you. It pains me more than I can tell you."
"My Lord, I have been harbouring a sorcerer. For that I offer the most sincere apology."
The poor boy had been forced to poison him, something the two servants had failed to mention. Gaius knew that he had felt incredibly weak and shaky when he woke up on the floor, but he had figured it was due to the goblin's abuse of his body, such as from the constant drinking Merlin had mentioned. He had never imagined the frailty was due to his body almost dying from poison, let alone poison Merlin had been forced to make and trick the goblin into consuming.
"You've poisoned me. You poisoned Gaius!"
"Leave his body while you still can!"
He had made Merlin live two of his worst fears without even knowing: being sentenced to death for who he is and losing those he loves.
Waking up from that memory laden dream was like jumping from the blistering heat of the summer into a deep, icy cold well. He practically threw himself from his bed gasping and rushed up to Merlin's room to prove to himself that the boy was alive and well.
He didn't open the door at first, he just stopped and listened. He heard Merlin shifting about in his bed, which was all he needed to calm his mind. As he turned to go back to sleep, he heard the boy whimper.
Cracking the door open and peering into the room, the physician saw his ward tossing and turning on his hard bed clearly in the throes of a nightmare. As he approached, he saw tears pouring from Merlin's eyes.
"Nooooo! Not him too… Will and Morgana… Not Balinor and Gaius… I killed all of them… I was sure that one was the antidote..."
That last statement seemed a bit...odd to the old physician. Then,certain memories came together in his mind.
Gwen had rushed towards him and just as his vision failed, she gave a shriek. He heard the clinking of glass against glass right before he passed out.
"I was sure that one was the antidote..."
As Merlin sobbed in his sleep, Gaius's heart went out to the boy. He hadn't thought about how the goblin possessing him must have affected the lad. The boy had been willing to poison him to get rid of the creature, but with Merlin's kind soul, it no doubt pained him greatly to do it, and now Gaius realized with growing horror that the poor boy had needed to guess which potion was the antidote and leave it to luck if his mentor survived or not.
Merlin had been plagued with nightmare for weeks after his friend's death and struggled to sleep for months after he had been forced to poison Morgana. And now this had happened nearly a year after the boy's father had died protecting him. He couldn't imagine just how traumatizing this whole experience must have been for poor Merlin.
Without really thinking, Gaius reached out and began stroking the boy's hair.
"I am right here Merlin. You saved me. I am safe. It is alright."
As he spoke, the boy in the bed stopped fidgeting, and a small smile formed on his pale face. Gaius felt tears form in his own eyes. Merlin had a great burden to carry, and now he had added to the weight. Once Merlin seemed to be free of the nightmare, Gaius returned to the main room wide awake.
As he sat there brooding about everything that happened, the first bell rang. The sun wouldn't be up until the sixth bell at least. He doubted he would be able to sleep after finding out about Merlin's nightmare. Was this the first time this had happened? Had he slept though the earlier ones in his exhaustion?
Filled with worried energy, the physician lit a candle and set to work replenishing his store of potions. He made as many as he could with the limited amount of herbs he had in supply. He was in middle of taking inventory of both droughts and herbs when Merlin's door opened.
Merlin fumbled out of his room, and he practically fell down the stairs in his haste and fumbled silently over to the divider that separated Gaius's bed from the main chamber. From where the physician stood near the main door, he could hear Merlin's panicked breathing. When the boy saw the empty bed, he let out a heart wrenching sound than cut Gaius to his core.
"No no no no! It was just a dream… He isn't… I didn't…"
Gaius didn't let the boy say anything more. After that cry from Merlin, the old man rushed towards the lad. Right after the words "I didn't" were sobbed out, the man pulled his nephew into a tight hug.
"I am right here Merlin. It was just a dream"
The warlock wrapped his arm around his uncle and sobbed. He began to babble in his hysteria.
"I dreamed that you died. Gwen and I poisoned you to get the goblin to leave you, and then we couldn't tell which vial was the antidote. I gave you the potion I thought was it, but I was wrong. You died and everyone but Arthur and Gwen blamed me for it. I ran back to Ealdor, but Uther caught me and…"
The old man hugged the boy tighter, reassuring him.
"I am alive Merlin. You captured the goblin, and you found the antidote. None of the rest ever happened. We are safe. Hush my boy. It is alright."
The mighty Emrys held tightly to his mentor like a small child and cried. The uncle sat down with his nephew and allowed the tears to flow freely as he rocked the lad sobbing into his chest.
The next morning when the prince came to find his manservant, he found Merlin and Gaius sitting on the physician's bed, sound asleep leaning on each other. Arthur barely caught the door before it hit the wall, waking the pair. The royal could see the tear tracks on faces young and old alike.
Without waking the men, the prince backed out of the room and gently shut the door. He didn't need to ask what had happened. If something had kept the two awake and crying the night before, he wasn't about to stir those emotions up again. Whatever excuse Merlin made for this morning, Arthur would pretend to buy it.