"Of course," the Doctor said, shaking his head. If the situation had been reversed, the Doctor would've gone in a heartsbeat to his own daughter, Susan, or Jenny. He wouldn't deny Jack that. And he wouldn't have him worry by staying.

And three weeks wasn't that bad. He could hop that easily, maybe even take a quick detour back here to figure out what the light in the sky was. Then, pick him up. Like no time had passed at all.

Three weeks would probably be good, too. He was becoming far too attached to Jack. The space might be good for them.

"But if you need me," he said, opening the TARDIS door. "You call. There aren't any other grand spaces in time where I can't help, not for at least fifty more years."