The smaller of the two masked, overalled figures pulled a gag out of Umbridge's mouth, then stepped back, letting his larger companion brandish a wand.
"Umbridge, where is the Stone?"
"You won't get away with this. I'm in the Ministry!"
"One of your goons went and dug it up. Where. Is. It?"
"I don't know what you're talking about!"
"Very well. Marco?"
The larger one hadn't ever been a good spellcaster, what with being mute and all, but with the right wand-waving he'd overcome that with certain useful incantations. Like the Cruciatus Curse. His handler spoke over Umbridge's screams.
"The muggles have amazing soundproofing equipment, and no electronics are involved, so it doesn't care about magic. No one will hear you outside this room. Now." 'Marco' deactivated the curse, for now, so the victim could speak. "Where is the Stone?"
"We. Never. Found. It!"
"Bullshit. Marco!" There was only so much convulsing that Umbridge could do while bound to that chair, her wand broken in half and the halves in two different rooms. Still, the director of this could sense 'Marco' enjoying the process, and frankly, it unsettled him; he'd been like that himself, during that awful year... "That's enough. This is your last chance before I Veritaserum you. Where is the Stone?"
"That's classified information!" Interrogation survival techniques were never standard Ministry training.
"So you do know. Marco, give her the serum." The Minister struggled, yes, but even without many spells memorised 'Marco' was utterly formidable in terms of pure strength, almost like Hagrid that way; soon enough, she slackened, her gaze became unfocused, as the ensorcelled liquid poisoned her system. "When did your goons take the Stone?"
"Some months ago, during the summer holidays at Hogwarts." The same flat, emotionless tone that the younger Barty Crouch had had. Yes, it was working.
"How did they locate it?"
"A team trawled the Forest, casting Accio on the stone until they were close enough for it to work."
"Where is it now?" She informed him, and not the audience. "Why?"
"...I wished for the Clave to have the Hallows for study."
"So they are real, after all..." The masked one shook his head, and took off his mask. "We'd have to get rid of you anyway, and I can't breathe in this thing. Do the Clave have the Elder Wand?"
"Yes."
The formerly masked man uttered a cluster F-bomb that would never appear in any of J. K. Rowling's books. "I know Dumbledore said that being the Master of Death didn't mean you were any stronger. But he never had all three... You know what? This is boring. Marco, Legilimens her, then shoot her." Harry had seen enough Muggle serial killers; the soul-rending of Avada Kedavra, the horrible self-inflicted fate of his adversary, was because of the energy the spell needed not the murder it committed. He turned and left the soundproof room, left 'Marco' to do the particular evil thing he did best.