Eccelston
The Executor's TARDIS materialized inside the Doctor's TARDIS at the bottom of the steps, in front of the doors, appearing as an exact copy of the Doctor's TARDIS down to the shade of blue paint. The door opened and the Executor appeared.
"I'm just saying one trip round the galaxy," the Doctor urged. "Just a quick jaunt, it's been forever since I flew another TARDIS."
"Not going to happen," the Executor said. He looked at his ship grimacing "Really?"
The Doctor turned and grinned. "Ah well, when in Rome." He gave the Executor's TARDIS a pat on the side. "Besides, your old girl has never looked better." He saw River standing at the console. "Hello sweetie, ah! I've done it again. Sorry, that's your line." Prancing up the steps, he gave her a kiss on the cheek. He paused, seeing the look on her face. "What?"
"I'm so sorry, sweetie," River said, her eyes overflowing.
The Doctor frowned and took her face in his hands, kissing away her tears. "River, no. We did it. We saved Max and his son; we stopped the military from constructing another Infinity Bomb ever again. I couldn't save Doctor Hardy but," He turned and gestured toward the Executor, "I didn't need him. You told me I'd need him but I didn't." He paused considering the implications. "Why would you tell me that? Why would you convince me to get him if I didn't, I didn't need him?"
River took the Doctor's hands away from her face and looked past him to the Executor. "When you revealed yourself to me you said that he needed to find you. That his soul depended on it."
"Did I?" the Executor asked.
"This was what you were talking about," River said, "this choice." She looked at the boy. "It's time for you to make good."
"What?" Max asked, moving to his son, sensing danger. "What are we talking about now?"
The Executor walked up the steps to the console, staring at the little boy. His voice heavy and final he said, "I understand."
The Doctor looked to the boy, to his father, to River, the Executor. The Executor's reached into his waistcoat. The Doctor leaped between the other Time Lord and the father and son. "No!"
"Doctor!" pleaded River.
"What is this?" Max yelled grabbing his son.
The Doctor turned slightly to Max. "I was focused on the wrong mind." He growled in frustration. "I thought it was Doctor Hardy but it was Stewart. His was the mind that needed changing." He held up a hand towards the Executor. "I haven't failed yet. It's not over. I can still do this."
"Doctor, look at him," the Executor said, his voice flat and even. "Look at him and see. The condition is terminal, Doctor."
"I do not believe that!" the Doctor ground out.
"Remember the last time you didn't believe?" the Executor asked; his tone devoid of sarcasm or judgment. "This need not be your burden to bear. Not this time. This is for me. I'll get it done. I am the Executor. Execution is what I do. In all its forms."
Despairing, the Doctor looked to River finding her equally distraught but resigned. He turned to Max huddled around his son. In the boy's eyes he found the truth of everything. The weight of it threatened to bring him to his knees. He looked back to the Executor, stepping forward; his maverick in hand.
"You can't do this!" Max pleaded. "He's a boy! What kind of people are you to save him and then kill him?" He pulled his son tighter to him. "I can watch over him. I can make sure he doesn't do anything like this again!"
"That's no guarantee," the Executor said. "The solution to the equation is in his mind. With it he could unravel the universe."
"But he'd need resources, yeah?" Max said. "We don't have that anymore. He can't even lift the tools." He began to cry. "Please, just wait!"
The Executor raised his maverick, his expression cold. "I'm sorry."
The Doctor straightened. "Stop!" He held up his hands. "Max is right. They don't have the resources. All we need to do is make sure they never have them and the danger is neutralized."
The Executor lowered his maverick narrowing his eyes. "What are you thinking?"
The Doctor gestured. "All we need to do is put them in the perfect place in time; somewhere technology will be too primitive for him to do anything and I think I know where."
"I don't care," Max said. "Drop us off in the Stone Age. Just don't kill my boy."
"I don't think we'll have to go back that far," the Doctor said.