Who: The Ninth and Eleventh Doctors
What: The Ninth Doctor realizing he should implicitly trust future incarnations
When: Sometime on the 23rd
Where: The Ninth Doctor's apartment
He doesn't bother responding to his past self. Instead, he sends his thoughts outward. With his new powers, it's not difficult to locate the other timelord. Taking the time to psychically shielding himself from anyone watching, diverting their attention away from him, he takes hold of his power and focuses on his physical form and the fields and forces surrounding it. This is more difficult than the other things he's tried so far, but he's a quick study. Though it may have been nearly impossible for a human to affect the area around him so deftly, he swiftly rises into the air, levitating himself quickly toward the Doctor's apartment.
When he reaches the window, he closes him eyes and, still levitating, reaches out to the atoms in the wall. He arranges them to his liking, restraining them so that their electromagnetic field and his don't interact - then walks straight through the wall as if it weren't there. Without the forces repelling him, there's plenty of open space to move through in the structure of the wall.
He turns toward the younger man, standing unseeing just a few feet away. He drops his shield and knocks on the inside of the window, a satisfied smirk on his face.