- "You just…” [She smiles] “..you remind me a lot of someone I used to know. You’re sweet Matt, kind and I think Elena was crazy to let you go."
- —Ally talking to Matt.
She met Matt when she talked to Tyler, who she had told to find a ride home when he drunkenly hit on her, asking him whether he safely got a ride home. After Tyler stormed off Matt apologised for Tyler’s behaviour. From the moment Ally met Matt he reminded her of somone she used to know, namely Joshua North. This meant that she found it comforting to talk to him, as she missed Joshua. She and Matt became closer during season 2, and even could have been described as actually dating for a while. Toward the end of season 3, however, they decided to remain as “just friends”. Matt never said it but he was concerned by her close relationship to Klaus, not in a jealous way, but in a Klaus-is-a-psycho way.
- "Stefan, Ally is trying to “Lexi” Klaus, not even Lexi would see any point in trying to “Lexi” Klaus. She cares, and I don’t think she can help it."
- —Damon worried about his sister
Klaus and Ally met during the early 1960s, New York– 1962 to be exact. The two were "partners in crime" during a period of 13 years, between 1962-1975, while Ally had her emotions off and was killing indiscriminately. Klaus was intrigued by the information he was being passed about a ‘ripper’ called Allyson Salvatore, having met Stefan in the 20s. He sought her out, hoping to find a monster of equal caliber to her brother.
Not disappointed, Klaus had fun during his trip to New York to meet the younger Salvatore. Klaus asked her to join him on his travels, it being during her impulsive phase, and as she was becoming bored of her escapades in the Big Apple, she accepted Klaus’ offer. The relationship blossomed into a friendship over the years, as they bonded over the thrill they got form killing innocent people, something they referred to as an “art”.
Over the thirteen years they spent together, Klaus and Ally grew closer, as people do. This eventually led to Ally starting to feel actual love for Klaus. This was problematic for their lifestyle of fun, violence and debauchery, as love meant emotions, and emotions meant the eventual tendency to feel guilt for exactly the kind of things she and Klaus were doing at the time. The problem never needed to be addressed in the end, as while visiting London in the mid 70s; the two were tracked down Michael, Klaus’s ‘father’. Not wanting to drag Ally into the mess, and wanting to get out of there pretty fast, Klaus wiped all memory of him from Ally’s memory, (as he did with Stefan), Ally instead remembered all of the killing and violence, but she remembered doing it alone, as she originally would have been.
Between then and the modern day, Ally regained her humanity and sought redemption for her dark years, feeling the full weight of guilt to go with her apparently innumerable death count. Ally was no longer the vampire she had been when Klaus had last seen her. So, when Klaus returned he was surprised to see that the youngest Salvatore, as well as her brother were now on the no-kill wagon, Stefan perhaps more so, what with his all-animal diet. Ally was more-or-less back to the way she had been before she went through her ripper stage, she was rational, she was sympathetic and she was in control of her urges. Only this time she struggled with her guilt, even after all this time. Though he didn’t let on to knowing them, Ally and Stefan didn't know that they had met him before yet and intended to keep them thinking that for a while.
During the events leading up to the ritual, Ally attended the decade dance with Matt Donovan. She was led out of the dance at one point by Klaus requesting her favorite song, he even added a message that it was “Dedicated to Ally from Klaus”. Expecting some kind of attack, Ally excused herself asking Matt for a “raincheck” before leaving the gym. Once she was outside of the school, she was incapacitated by Klaus' witch and taken away. She woke up half a day later on the floor of Alaric’s apartment with a still pissed off Katherine. When Stefan went to Alaric’s apartment asking Klaus for the cure to a werewolf bite, he ushers a compelled Ally over, and demonstrates his blood being the cure. He insists Stefan and Ally join him in his travels in exchange for allowing Ally to take a vial of his blood to Damon.
Finally, during what Ally sarcastically refers to as Klaus’ “magical mystery tour” of North America, Klaus ends up finding himself reminiscing aloud about a summer in Tennessee, he then drops Ally’s name, causing a her a bit of confusion.