"Wha've I done? Setting a bleedin' 'ouse-elf on me, what are you playing at, wha've I done, lemme go, lemme go, or - "
-Mundungus Fletcher (DH11)
"Perhaps just one more, Master Harry, for luck?"
-Kreacher, on being told not to hit Mundungus over the head with a saucepan (DH11)
Dung informs them that the locket went to Umbridge, who wears it at the Ministry of Magic.
Mundungus Fletcher is not happy about being abducted by Kreacher, and there is a brief struggle upon their arrival – with Mundungus getting disarmed by Hermione and tackled by Ron. Before Harry or his friends can ask Dung about the locket, the detainee tries to justify his abandonment of Moody during the Battle of the Seven Potters and to defend his stealing from 12 Grimmauld Place in general. Finally, Harry gets a word in edgewise. Dung then explains that Umbridge had confronted him about selling items illegally, but let him off in exchange for the locket. (DH11)
Three days earlier, Kreacher explained that he did not know what had become of the locket Horcrux after it was stolen by Mundungus Fletcher, and Harry sent Kreacher to retrieve Fletcher so he could tell them where the locket was.