The main reason Tonks was drawn to it was because she saw a very familiar glass eye. It was an eye much like Moody's, also known as "Mad-Eye."
Both Tonks and Mad-Eye had known each other for a long time, but not through the Order of the Phoenix. Tonks joined the Order of the Phoenix quite late, when Voldemort returned.
Why wasn't Tonks one of the original members of the Order? Because she was too young. Tonks, due to her mature appearance, always gave the impression of being a reliable and mature older sister, but in reality, she had graduated just a few years ago.
She and Charlie Weasley are of the same generation! Charlie is only eight years older than Ron, and from the perspective of Muggles, Tonks and Harry could be considered the same generation. However, from the wizarding point of view, the age difference between Tonks and Harry is about half a generation.
The wizarding world, due to its special entry schedule and education system, has always had a confusing sense of age. Since wizards start school at the age of 11 and graduate seven years later to enter the workforce, many students enter the world at the age of 17 or 18. This is comparable to the age of a high school student in the Muggle world.
This makes the actual age of many people not match their perceived age. For example, Harry's parents always appear to be in their thirties when in reality, Harry's father, James, was born in 1960 and died in 1981 at the age of twenty-one. Calculating Lily's age when Harry was one year and ten months old, Lily was probably nineteen, which is completely inconsistent with the common perception!
But as Tonks' parents leaned towards the Order of the Phoenix, she caught the Order's attention and began training as an Auror under the watchful eye of Mad-Eye Moody, a member of the Order, and officially became an Auror this year, which probably equates to graduating and pursuing a Ph.D., thus obtaining the highest title in the wizarding world.
Due to her familiarity with Moody, she knew the wonders of his eye. She originally thought that this kind of high-level alchemical item was unique in the wizarding world, but today she saw it in a dirty and dusty shop.
"What's this?" Tonks pointed to the box and asked.
"The Hand of Glory," Mr. Borgin explained with some effort to cheer up. "If you place a candle on top, only the person holding it can see the light. It's the best friend of thieves who don't want to disturb others at night."
Tonks mocked Mr. Borgin's words. She couldn't help but hear the double meaning in them: this object called the Hand of Glory was perfect for thieves. It was also difficult for Mr. Borgin, who in such a short time could come up with a plausible explanation for the Hand of Glory.
"No, I don't mean that; I mean the eye," Tonks said, ignoring the Hand of Glory and the blood-stained poker cards next to it as she pointed to the glass eye.
Borgin: "I don't know."
He realized that Tonks was not a regular customer, so he had no obligation to answer her questions. It was a reflex of his professional illness to have instinctively responded to her.
Tonks realized she had a complicated problem: Borgin refused to answer her questions, and she couldn't do anything about it. For the next fifteen minutes, no matter what Tonks asked, Borgin always responded with an "I don't know" attitude or gave superficial explanations about trivial matters. This kind of response did not reveal the connection between the shop and dark magic at all.
But it wasn't all bad for Borgin, as most of the tagged items were confiscated by Tonks, and the shelves of what looked like human bones were secured by her.
"I know you're not telling the truth, Mr. Borgin, but it doesn't matter, there are people who know more than I do." After a frustrating quarter of an hour of guessing, Tonks finally couldn't contain herself. She took a deep breath and forced herself to calm down.
Knock, knock, knock!
The sound of a wooden staff hitting the floor in front of the shop's door was heard by Borgin, who initially froze and then turned pale.
With the ringing of the bell, a man appeared at the shop's door, holding a massive staff and wearing an oversized coat. He was already older, as his long hair had turned gray. Anyone who saw Moody for the first time would understand that he was an experienced warrior, as every inch of his skin seemed to be covered in scars, his mouth was like a twisted wide gash, and his nose had disappeared where it should be prominent.
Making a knocking sound was his prosthetic leg. However, the prosthetic leg was not his most notable feature. He had two eyes: one very small with a black pupil and the other very large, with a distinctive bright blue color, which constantly blinked and moved from side to side, unrelated to the normal eye.
When he saw this man appear, Mr. Borgin's breath seemed to stop. The thugs surrounding him also opened their eyes and looked at the stranger at the door, a name was on the tip of their tongues: Alastor Moody. The most prominent Auror of the modern era, the hero of the wizarding war, the guardian of Azkaban's Dementors. It was said that half of the Azkaban Death Eaters had been sent there by this Auror.
Tonks' expression softened for a moment, she smiled at Moody and said, "Sorry to interrupt your retirement, Alastor. But I could really use your help with my identification, please."
"Very well," Moody replied briefly and began to pace around Borgin & Burkes, his glass eye rapidly spinning. Finally, his gaze stopped on a bag that one of the thugs was holding, containing the loot they had obtained from this shop.
"For me, fighting Death Eaters and dark magic can never be considered a bother," he said, first echoing Tonks' words, and then pointing at the bag. "Is that all you've confiscated? Half of it is fake!"
Moody's raspy voice echoed in the shop, and an uproar ensued: Counterfeits? How could it be? Had they fooled Borgin when he picked up the merchandise?
Moody pulled out his wand and, with a flick, several items that Tonks had stored flew out of the bag and fell to the floor.
"All of these are fakes, the real ones are... here!" Moody limped over to the counter, raised his staff, and slammed it against the counter. A screech of chains and gears was heard.
The counter slowly rose, revealing a large cabinet emerging from the floor.