Number Four, Privet Drive, Little Whinging, was an average, normal, household, in a normal, average neighborhood. No one in the house appeared to be anything but ordinary, or do anything but ordinary things. Its inhabitants appeared to be three normal, average, overweight citizens, and a fourth skinny child whom nobody knew much of.
It was to this house that the TARDIS suddenly heaved out of the Vortex, and landed on the corner just down the street. The Doctor was thrown off his feet and into the nearest wall. "Oi! You could've given some warning!" he snapped to the machine. But he patted the wall fondly before pulling on a long, brown trench coat and exiting.
Though it appeared to be a lovely spring afternoon, there were no children playing outside in the streets, save for one skinny boy outside House Number Four, and he disappeared inside the house a moment later.
The Doctor shoved his hands in his pockets and meandered down the street, whistling. Obviously the TARDIS thought he should be here, and he might as well investigate a few things while he was at it. The whole block seemed boring-inexplicably boring, in fact-but, well, things were not always what they seemed. This notion was surmised by the fact that once the Doctor reached house Number Two, he found that he could go no further.
He tried running (honestly, would he never learn?). He tried sidling. He tried crawling, licking, sniffing, sonicing, kicking, punching, and in general trying to get past the invisible wall blocking his path.
Off-handedly, he wondered whether this was the reason the TARDIS brought him here.
The solution to the never-moving wall became clear when the TARDIS made a funny little humming noise in his head, almost like saying 'I told you so.'
"You didn't tell me anything," he admonished when he was back inside the control room. "Now, let's see if we can make a nice little space hop. Wait-" He peered at the screen as a large blue police box materialized down the street. "Brilliant. Let's go to a few seconds ago. Allons-y!" He threw a lever and pounded the console with a rubber mallet.
Thirty seconds ago-relative time, of course-the TARDIS landed on the other street corner. The Doctor strode out the doors and made his way back down the street, unhindered.
Until he ran into another barrier just in front of Number Six.
He didn't even attempt to go through it again and spun back to the TARDIS. Number Four-the boy-it had to be of importance.
He made a little hop to London to check the directory in the registar's office, to see who lived in Number Four, and it never occurred to him that he might be a few years late, on accident.