"So." The Doctor straightened up and smiled, clasping his hands briefly in front of him in a childish manner, even rocking up onto his toes once before those hands released and he leaned forward just a bit. "You're our Jack's Plus One then, are you? Never thought I'd see the day. Well, very pleased to meet you." He lifted a hand then and wiggled his fingers, a bright smile spreading out over his face. "Hello there."
But with the pleasantries out of the way, the Doctor was once again straightening up. "Let me guess, Torchwood? Only Torchwood stares at me the way you are." But he did reach out to take the device and look it over. The Ninth Doctor was a bit more focused, a bit more task-oriented than his earlier (and later) counterparts. But it didn't mean he couldn't have fun, and he was smiling then and lifting the device to wiggle it some. "Two TARDISs. You know what that means, don't you?" He even paused for dramatic effect before tossing the device back into Mr. Ianto Jones' hands. "Absolutely nothing."
And with that, he was turning to continue walking towards the source of the singing, and the source of the signal for the other TARDIS. It meant that something was very wrong.. others had been able to navigate his TARDIS before, but that meant nothing.. what meant something was the singing. Was the fact that perhaps Rose was in that TARDIS and had been brought here as well, from the future -- from his future. Really, it could have been anything, so it all meant nothing until they found out just what was going on.
"Come on then, all aboard." Called back to the other two as he walked. "Jack and his Plus One." That part was said more to himself. "Off to save the day together, like one big happy family." He flashed a smile back at the pair as he said it, expecting the two to catch up, of course. "Let's go, then! This is going to be fantastic." Another TARDIS. Another Time Lord. Another Doctor? In all rights, he knew he shouldn't be going.. if it was another version of him, it was a paradox, and everyone knew that paradoxes were bad, naughty, evil things. But when had he ever been able to resist before? He wasn't going to start now.