In Dumbledore's office was a treasure called the Pensive, which allowed him to store memories and observe the memories of others.
Dumbledore opened the door to his office and led Tom inside. The Headmasters on the wall were awake and chatting in a group, and when Tom entered, they just looked at him and went back to their conversation. Fawkes, Dumbledore's Phoenix, was on his branch as usual, his head buried in his wings as he slept.
There was a shelf behind Dumbledore's desk, on which hung the Sorting Hat. Next to the hat, in a glass case, was a gleaming sword with a ruby the size of a pigeon's egg in the hilt. This was Godric Gryffindor's sword, and it was there for a true Gryffindor when he needed it.
Dumbledore went to a black cabinet and pulled out of it a shallow stone basin, the mouth of which was engraved with runes and some other mysterious symbols, and which had been filled with a silvery substance that was both liquid and gaseous like a cloud. The mysterious substance was like silver, but constantly flowing, rippling on the surface, spreading and swirling like a cloud.
It was as if light had become a liquid, or as if wind had condensed into a solid.
"The Pensadero is a tool for mages to store their memories. Most Pensaderos will be buried along with the wand when the owner dies, because the memory inside has a strong personal color. However, there are also Pensers that will bring back memories that are passed down from generation to generation by wizards, such as this Pensive at Hogwarts." Dumbledore walked over to the Pensive, pulled out his wand and stirred the memories stored in it.
The penetration of the wand caused the surface of the silver object to spin faster, and even a small vortex faintly formed.
"Sometimes I feel like I have too many thoughts and memories in my head, and that's when I use the Pensive," Dumbledore said, pointing to the stone basin, "To suck the leftover memories out of my head with my wand, pour them into this basin, and look at them when I have time."
Tom looked at the Pansy and saw that a faint figure had emerged from it.
"The human brain only develops and uses a small part of it," Tom retracted his gaze, "Professor, did you know that? Human memory is divided into two types: surface memory and deep memory. Many times we think we have forgotten something. But we haven't, it's just lying dormant in the depths of our brain."
"There are many reasons to forget, time, pain, external forces, memory is the best asset a person can have, isn't it?" Tom's wand had appeared in his hand, "Professor Dumbledore, can I borrow your Pensive to store some memories? I trust that you, being the man you are, would not peek into them."
Dumbledore smiled and nodded, swearing that he would not peek into Tom's memories and that he would never eat sweets again if he broke his promise. After taking the oath, Dumbledore showed Tom how to extract the memories.
Tom believed that the Pensive was meant to preserve the wizard's "freshest" memories. It is important to understand that memories "fade" over time, changing details in ways that the owner of the memory could not foresee. For example, the first day of military training is certainly not the same as the last, and the last day may add an unexplained filter of embellishment to the first.
But if you extract the memories at the end of the first day, you get the "freshest" and most original memories of the training.
Tom wanted to do this because he realized that the memories he had seen of Lockhart were beginning to blur, especially the memories of the people Lockhart had stolen, which were changing in detail. These memories, which were becoming tainted with his own and Lockhart's, were unacceptable to Tom.
So he had to extract these memories and keep them pure.
Tom followed Dumbledore's instructions and rested the tip of his wand on his temple. When he withdrew the tip of his wand, there were strands of silver-white hair stuck to it. Tom put this new memory into the Pensive and saw several strange but familiar wizarding faces floating in the bowl. Holding the Pensive in his hands, Tom spun it like a gold digger spins a sandbox until the memories sank.
When it was all over, Dumbledore walked over to Tom and added Evans' jar of memories to the meditation pile. Suddenly, the scene in the Pensive changed, and Dumbledore approached the Pensive with Tom.
Tom strained his eyes to see inside the Pensive, and discovered that beneath the silver memories was a wagon-like scene, with Tom looking through the skylight of a train.
Did it look like a Muggle train? Judging by the inside of the carriage, it must have been a first-class seat, but Tom was sure it wasn't the Hogwarts Express. The characters in the lower compartment were all adults dressed as Muggles, and by their appearance and movement, they were all passengers on this train.
Dumbledore took Tom's arm and pulled him closer to the Pansy.
"Watch me do it." He demonstrated to Tom as he approached the Pensive, bent down and plunged his head into it. The depth of the Pensive was such that at most it would have covered Dumbledore's cheek, and not even his sideburns would have gotten wet. Instead, the Pensive swallowed Dumbledore like a bottomless abyss.
Tom followed suit, bending down so that the tip of his nose touched the surface of the memory in the Pensive.
In an instant, Dumbledore's office flipped, and Tom felt a suction in front of him, as if he were on the edge of a vortex, and he rushed forward, headlong, into the Pensive. The memories in the Pensive were shiny silver, but after falling into the Pensive, Tom felt himself falling through a cold, dark substance.
Tom found himself in a fluffy, roomy armchair with plenty of space in front of him and a small shelf for his luggage. In front of him was a neat and tidy table, and in front of it sat the kindly old wizard Dumbledore.
He pointed behind Tom, who looked in that direction and saw Evans sitting diagonally behind him. Even in the Muggle world, Evans wore his monocle, double-breasted coat and bowler hat. Going back eighty years, there was nothing out of place in this outfit. But in the 1990s, it was a little out of place.
Evans, at this moment, is earnestly looking into a Muggle "mirror," while the other passengers in the carriage are going about their business: reading, writing, or just resting their eyes.
None of them were playing with their cell phones or video games, as none of these portable devices had been invented yet. There are always people who make fun of foreigners for reading books in the subway, but those people have never been abroad. They don't know that foreigners read books on the subway because they have no signal.
In the last couple of years, the signal has become more widespread and they play with their cell phones quite a bit.