Sirius was carrying the unconscious Harry toward the Forbidden Forest.
Before entering the Forbidden Forest, he took out the Dark Mark bead. After activating it, he immediately said in a fawning, ingratiating tone, "Master, I'm about to take Harry Potter into the Forbidden Forest. Do you have any further instructions?"
A gentle voice came from within the bead. "It seems things have gone smoothly... My people will meet you before the others do. As long as you hand Harry Potter over to them, your mission will be complete."
"Of course, they will injure you and make it look as though Harry Potter was taken from you. You must continue lurking at my Undying Clone's side."
Sirius had recently become quite adept at flattery. "It is my honor to be injured for Master!"
A satisfied laugh came from the bead. "Very good! Wormtail, when you return, I will reward you handsomely!"
The bead dimmed once more.
"You seem well suited to this role," the "unconscious Harry" on Sirius's shoulder said.
"I was forced into it." Thinking of the "unconscious Harry" slung over his shoulder, Sirius could not help rolling his eyes. It was actually Matthew in disguise.
Until Matthew had teased him while posing as Harry, he had not noticed anything unusual at all.
Apparently, this had been Dumbledore's idea. He had keenly realized that the actions of the two Voldemorts were not simply an attempt to murder Harry. The younger Voldemort was preventing the Undying Clone from obtaining Harry, and there was likely a deeper purpose behind it. Dumbledore vaguely felt that it was connected to Voldemort's resurrection.
Therefore, Dumbledore had Matthew disguise himself as Harry. They would leave a few Death Eaters alive to take "Harry" away and see what Voldemort intended to do after obtaining him. He had