[The Doctor emotionally withdraws. He knows that is what Harry Potter is about. He knows that love is powerful. After all, it did change him, very much so and quite literally. However, he's not sure if it was worth the pain in the end. It's quite clear in those brown eyes that someone did love and lost. What's the Shakespeare quote? Better to have love and lost than to never have loved at all Can an immortal being love a mortal. Had it been worth it lying to himself and lying to her verbally when she asked him directly if they were a couple. Does she know that he was on the other side of that wall trying to reach her? Of course she was. He could sense her. Feel her soul even in another dimension. But he couldn't stay there. What good would that do? Ten whispers to himself]

The Cyberman was right.

[As he reflects back on this. Thankfully, the follow-up distracts him from his depressed thoughts of his lost Rose.]

Oh? Where have you been? Blimey, how'd you end up there?

[Then silence]

Different universes... [His eyes dash across. Not impossible. In fact quite possible. He's been to a few other universes before. Peter Quill.]

Nope, sorry not ringing a bell.

[There is a way to test this theory.]

Good to meet you, I'm The Doctor.

[If Peter has traveled the Galaxy and it is a Galaxy that has The Doctor. Peter should have heard of The Doctor. ]