In order to obtain more food Jared gave Nina, then Aaron, away to a group of vampires. Finding himself in a blood farm, it is revealed to Aaron that he is to be turned into a vampire foot soldier.
Before this can happen however, Jared arrives and distracts the vampires. Aaron flees and hides until the sound of fighting dies down. Emerging he eventually finds his sister and uncle surrounded by vampires. The vampires turn Jared, who then attacks Aaron (giving him his characteristic scar). Jared then has a brief flicker of humanity, allowing Nina and Aaron to escape.
Running, the pair find themselves trapped, though Bernard Senior rescues them.
Aaron is first introduced in Storyteller, where he is on guard duty (preventing Annika and Nathan from leaving). Here he begins to tell Nathan a story (which is in fact his own background) however he is interrupted before he can finish.
In Operation Rescue Doc he is shown once more assisting Annika, Rusty and Nathan (helping them move into their new housing) when he is told to come assist in the military operation to rescue Doc. It is presumed that he helped out in the operation, though he is not shown in person.
Aaron's next appearance is in Home Alone, where he delivers Scrufflebeck to Joe. In Ms. Pink Lace he is shown to have hit the town, alongside Joe and Rusty. Sat with the other two Aaron is curious as to why Bernie and Jess would have left Joe their apartment. Annoyed by his questions Joe storms off, causing Aaron to follow him.
In The Rest of Aaron’s Tale, Part 1, The Rest of Aaron’s Tale, Part 2 and The Rest of Aaron’s Tale, Part 3 Aaron finishes his tale, before taking Annika and Nathan into town. Here Aaron buys Annika a new sweater and promises her a new couch.
After some looking they eventually meet Nina, who runs off with Nathan. At this moment Aaron asks Annika out to lunch, though she refuses, saying that she'd instead prefer to watch out for the children. At this moment Aaron is also called away to take part in Bernie's mission to retake Doc.
Upon Doc and Rosa's return, Aaron is one of the first to recognise her and enquires as to how she ended up a vampire.
Present with the rest of the Night Stalkers, he meets Samuel. He completes his mission and returns to New Hammerston along with the others. Upon returning he goes and meets Annika and his sister, and takes them out to lunch.
He is shown walking with Annika, Nathan and his sister through New Hammerston, where he makes a small faux pas in mentioning Scott.
Following Victor's rampage Aaron goes to try and stop him, though is knocked out. Waking up later he discovers Annika's body and begins to mourn, though is rushed away by Samuel.
Alongside Samuel and the others he manages to escape the city to Bernie's base, though is unable to get in. He is then approaches by Jake, who tries to get him away from the base. After something of a showdown however, Bernie wakes up, and activating Harry, Jake pulls back (though not before removing Aaron's rank). The pair then head into the base, where they discuss their plans for the future.
Aaron is shown to be one of the calmer, if more naive characters. Generally optimistic he is shown to have great faith both in humanity and in Bernie and Jess especially.
Aaron generally gets on with most other people, though he does clash with the more uncouth characters (such as Rusty).
Aaron seems to have taken an interest in Annika. While she seems to be friendly with him, she doesn't appear to reciprocate his feelings.
Aaron seems to fit the role of the standard big brother. While he shows concern for his little sister he seems to tire of her antics.
Aaron can be expected to be more capable than the average human soldier, being in the Night Stalkers. Nina mentions that he's been on a number of missions before, so it can be assumed he can handle himself quite well.