This Page is about the Lore of George and Karl. If you were looking for the Dungeon Run Boss, click here.
This will be a recap of the full story of George and Karl (Lore) until Descent of Dragons, so that it can be finished in that Solo adventure.
Journey to Un'Goro[]
In Journey to Un'Goro, George and Karl were easter eggs in the flavor texts in two Paladin cards. In the first, 
Lost in the Jungle, the flavor text says: George and Karl were never heard from again. This gives the implication that the two Silver Hand Recruits summoned are George and Karl. In another card, Vinecleaver, the flavor text says:George and Karl! Thank the light we found you!, showing that they were found by someone using a Vinecleaver. This may have been a hallucination, as they never were rescued.
Dungeon Run[]
In Dungeon Run, there is a boss named 
George and Karl, which is proof that they weren't rescued. It seems that they found an opening to the Catacombs in Un'Goro. It was presumably Karl's idea to enter the Catacombs, as the Opening Remark is "Light's sake, Karl! NOW look at where we are!".
Henchmania![]
In the Tavern Brawl Henchmania, George reappears, with the Flavor: Lost without Karl.. This showed that Karl might have been lost in the Catacombs.
The Dalaran Heist[]
The Dalaran Heist expansion included a henchman named 
George the Fallen. His emotes are based on vengeance, and one of his thinking emotes reads: "Are those adventurers even here...?" as if he thinks Karl got killed in the Dungeon Run fight. When you select him, he says: "I'll make them pay for what they did to Karl!". Using this information, it can be assumed that the League of E.V.I.L. lied to him about Karl, and that the murderers are in Dalaran so that he helps take out the Kirin Tor, which was his job in the Heist.
Tombs of Terror[]
The Tombs of Terror had a Signature Treasure for Sir Finley called 
Karl the Lost. His flavor says: "A friendly paladin who was found wandering Uldum. He seems to be looking for someone.". It seems he somehow appeared in Uldum, and he is now searching for George, who joined the League of EVIL.
Galakrond's Awakening[]
The two were finally reunited on the streets of Dalaran during the last hours of Rafaam's master plan. George, believing it to be a trick, battles Karl. After realizing that it isn't a trick, the two come back together.
Madness at the Darkmoon Faire[]
George and Karl visit the Darkmoon Faire as stated on the card 
Day at the Faire.