The key to controlling the dragon is a talking sword called Wayne?
Gawain is a magical sword seen in the BBC America series The Watch. A sentient magical artifact, it has the power to control a beast known as the Noble Dragon. Although Gawain is the sword's formal name, it refers to this name as its "stage name," and insists on people referring to it as "Wayne."
The Watch captures the sword and soon learns that there are other artifacts besides Gawain which are needed to control the dragon and that Gawain might have knowledge of them. They try to interrogate it, but find its answers irritatingly vague. Sam Vimes, the Watch's captain, then takes the sword, saying that he has new orders. He informs them that he's dumping the sword in a magical disposal lake, supposedly on Lord Vetinari's orders.
He is pursued Constable Cheery and Lady Sybil Ramkin, who argue with him over the morality of his plan of destroying an apparently sentient sword as they traverse a wasteland of thaumic energy filled with failed magical artifacts created by the Archchancellor of Unseen University. As vimes is beset by a nightmarish vision of his past, Ramkin tries to claim the sword, thinking it will bring her the power she needs to finally change the city of Ankh-Morpork, based on her own fears about the failures of her past efforts. Vimes ends up reclaiming the sword and the group reaches the edge of the lake.
There, Ramkin makes one last plea for the sword to be saved, but Cheery tells Vimes that he must do it. As Vimes tosses the sword, it shouts that it's Vimes's brother. It travels an arc to the lake, but before it can hit the water, a massive hand reaches out and grabs it. "It's a lady of the lake," declares Cheery, explaining that these form in bodies of magically enchanted water. The Lady tosses back the sword, which pierces one of Vimes's boots, shouting that it is not, in fact, his brother. After they remove the sword, they begin asking questions of the Lady of the Lake, based on Cheery's advice. They learn that it does not want Vimes to dispose of the sword and they must resist. Carcer Dun and his group then arrive and take the sword.