The pattern started with the Pensieve – a basin of memory. The governing forces of it were straightforward: the basin formed a link with the spellcaster, allowing one to sift through memories. It needed to be powerful, so that it could find memories that even the spellcaster didn't know he had. It had to be meticulous – every detail was needed. Most of all, it had to be safe, for there wasn't much point to discovering a buried memory if he burned his mind out in the process.
Eric focused the patterns on sensation, sticking to those things directly sensed. He established rules for an indirect bonding, which allowed the pattern to operate aligned with the subject, rather than seeking to breach natural barriers. He introduced functions of chronology, so that seeing items in a presented image could provide a frame of reference from which to proceed. Finally, he brought in a control function to allow the subject to master the pattern logically, rather than allowing it to proceed relationally.
It took a month of charting by candlelight before Eric could finally look up to his house-elf with satisfaction. "Willy, I present to you – the Mnemolodion!"
The elf looked quizzically at the oversized page of loops, sigiled circles and ribbons. Finally, he turned to Eric and smiled. "Yes, it looks quite nice."
Eric chuckled. "It doesn't look like anything right now, but this defines the basic principles and elements needed to create a device to scroll through everything I've seen since I was born. With this, I should be able to find an image of my mother."
The process was a bit harder than it looked on paper. Because he was also pursuing his carpentry to keep the money coming, it was the end of July before an apparatus was constructed. The device was little more than a large brass circle in front of a mirror, with a long bar behind it. Two clamps held a fresh strand of Eric's hair, a small silver ring hanging upon it. On either side of the mirror sat small water dishes with floating candles.
Eric set the final adjustments, then drew out his wand. "Chrononimbus – temporus optix theatrum!" The words conjured light spilling onto the feeble contraption, which shook and shuddered in response. For a moment it appeared that nothing happened, then slowly a mist crept up from the water dishes, framing the mirror and swirling about the brass ring before floating centerward, in complete defiance to gravity, drafts, and common sense.
As Eric looked on, an image formed in the mirror. It was his drawing as he finished it several weeks ago. Looking beyond the image to the strand, he cast again: "Leviosum Officiux!" The silver ring floated with the hair strand centered. Eric took his wand and slowly arced his hand towards the ring, which responded by skimming back. As it did, images flashed and danced within the mists, far too fast for the eye to see.
Periodically, Eric stopped the ring and looked into the glass to see images of his childhood, all of which included one room or another on the Hogwarts grounds. However, the buildings seemed to grow taller and taller as the ring moved backwards, then finally it happened – there was an image in the glass Eric didn't remember, a room he didn't recognize. He could make out the fact that he was lying in a wooden frame – a crib, most likely. Suddenly he snapped his wand upward: "Frijix totalus!" The spindly contraption seized up and was absolutely motionless.
Within the mirror's image was a woman with long, jet black hair framing an angular face. Her eyes were narrow and sharp, her nose small and pointed, and her mouth a thin line that barely revealed lips. Each element would have, on it's own, perhaps seem sinister or unattractive, yet together they formed a very balanced presentation which reached to Eric's heart and pulled with a strength he hadn't anticipated. There was no doubt in his mind: this was the face of his mother.
His hands bolted to the paper in front of him, scrambling to sketch out her basic features. As much as he hated the time he was taking, more magic was out of the question since it could have serious consequences if it mixed poorly with the spells he had already cast. Besides, he was already wondering if the Ministry of Magic was growing suspicious with so many spells being cast at once. He couldn't chance another. While seeking as much accuracy as possible, he produced a passable drawing that highlighted her most striking features.
Eric released his holding spell and searched further. The dark woman appeared over and over. In fact, before his eyes spotted Hagrid, she was the only person he ever saw. His search upward and downward of the farthest reaches of his life were of no avail, and at length the mnemolodion fell apart under the stress. This didn't bother him too much. He didn't expect it to survive the effort, and it's continued existence may have ended up more trouble than benefit. He folded up the pattern-map he used to create it and tucked it into a leather pouch. Such things were valuable, and one never knew when such a thing might be useful again.
Eric looked down upon the sketch. It was a start, and quite enough to quickly pare down the list of people who could have been his mother. Yet as much as he had learned, he was slightly frustrated over the experience, for it was clear that he had never set eyes on his father.