The Doctor sat in his chair, alone. Peri was somewhere in the TARDIS, doing something. But, the Doctor was okay with that. All he wanted was some time alone, just him and his thoughts.
The Doctor thought about lots of things, companions he met, worlds he explored, people he saved. A jumble, a large web of things. So incomprehensible, yet so accessible, if only for the Doctor himself.
After a while, he fell into a deep trance, completely immersed in his thoughts, unaware of anything that happened around him. Then, his mind filled with new thoughts, thoughts he didn't unearth himself from that web of memories.
Thoughts of the future.
A fleeting glimpse of a man dressed in black time lord robes, laughing evilly up his sleeve.
An umbrella, but unlike his current one. This one was black with a red question mark handle.
Metal cans of something. Somehow, the Doctor knew what it was. Nitro-9.
A jacket with various badges and pins on it, with the word "Ace" stitched on the back of it.
Cheetah people. The Brigadier. An airship, the R101.
Suddenly, the Doctor felt a huge boom. Then another. This time, it wasn't a fleeting glimpse into the future. It was longer. Out of the rubble came Daleks. Lots of them. Time Lords in battle armor fired at them. One Dalek exploded. Death rays were shot from the Daleks' weapons, ending the soldiers' current incarnations. Would they regenerate? Probably not. Another explosion.
Then, suddenly, it was over. The quick, fleeting glimpses continued.
Bad Wolf. Carrionites. Cybermen. Weeping Angels. An electric guitar.
The pictures started to become fuzzy and distorted. Soon, it was just a swirl of color.
The Doctor woke up.
He was initially very confused as to how he saw these pictures. Did he consciously think them? Were they of the past, the present, or the future? He must be hallucinating.
He got up out of his chair and went to go check on Peri. He dismissed the scenes and pictures he saw as unimportant. Even the scene of the Daleks, which he was concerned about, soon faded from his memory.