The Doctor wanted to address the boy, when he saw Sherlock's eyes beginning to glow.
"No, don't," he screamed at Sherlock, feeling suddenly very, very cold inside.
The boy, John, Ayumi, Maylene and Sherlock lost consciousness with a pained scream, the cybermite falling off of their faces in the process, lying motionless on the ground next to their victims.
The Doctor was next to Sherlock in a second holding the younger mans body, who's eyes were still wide open.
"Why?" he asked, tears threatening to fall. He hadn't felt hurt like this in a long time. "You didn't have to do this."
"Doctor!" he suddenly heard Donna's voice next to him. Puzzled he looked up to her. Hadn't he told her to leave?
Donna was standing in front of him, holding a shining orb in her hand.
"Doctor, look" she spoke urgently. "I found this orb next to the boy."
Hope flared up inside of the Doctor.
"You have to smash it, Donna. Fast!"
So Donna laid the orb on the ground and smashed it with one foot.
An orange-like essence floated out of the broken orb back to the four unconscious Timelords.
Ayumi, Maylene and John slowly regained consciousness again, Donna helping them up. Only Sherlock remained motionless
"Come on, come on Sherlock," the Doctor demanded agitated, looking for any sign that Sherlock was waking up but there was none.
John kneed next to them, giving Sherlock a quick check up.
"We better get him back to Baker Street" he finally stated looking at the Doctor. "I can't say why he's not waking up, there's nothing I can do for him here. Also it's way too dangerous to stay. "
It was then when the Doctor noticed that the young boy and three of the cybermites were gone.
Carefully he laid Sherlock into Johns arms, then stood up.
"Take the Tardis to get back to Baker Street" he said, giving Maylene a key and urging them to hurry. "I need to take care of something else first. I'll meet you there. "
Without waiting for a reply he turned away and vanished into the opposite direction from where he had come before.
"What can be more important now?" Ayumi wondered out loud, shaking her head.
Donna noticed the absence of the boy and indicated it.
"I'm going after him" she decided. "Are you going to be fine on your own?"
Maylene nodded.
"I know how to fly a Tardis, don't worry. We'll take care of Sherlock, you make sure the Doctor does nothing he'll regret in the end."
And so they parted ways again.
It wasn't that hard for the Doctor to follow the cybermites. Their circuits were seriously damaged, so the boy was moving only slowly.
The Doctor caught up with him at the teleportation device, using his sonic screwdriver to lock it down.
"Oh you're not going anywhere," the Doctor spat, full of anger and hatred. "It ends here and now."
The boy looked up at him smirking.
"So you're going to kill this little one?" he asked, pointing at himself. "Because I can tell you he's still alive."
The Doctor took some careful steps forward.
"I don't care." he replied coldly. "I don't care if you think you can bargain with his life because it won't work."
"Do you think Sherlock would like to hear that a child died because of him?" Donna begged the Doctor to consider. She had arrived just in time to hear his last words and was visible worried. "There has to be another way"
The Doctor looked at her and seemed to calm at least a little bit.
"Let us go" the boy spoke up again. "We're leaving this planet and never return. We keep the little one alive, we promise."
"Then leave," the Doctor ordered unlocking the teleportation device, but when the boy stepped in and activated it, he used his sonic screwdriver on the device again.
There was a short, awful screech from the cybermites as they vanished, the boy stayed inside the device, lying unconscious but alive on the ground.
"Where have they gone?" Donna asked silently, a little bit unsettled by the strange sound.
"Cease to exist" the Doctor replied emotionless, picking up the boy from the ground then turning around to leave.
"Let's get him to a hospital" he added as he passed his companion and Donna nodded with a sigh.