The school that Allison died at was being attacked by the beast so what Artemis had to do was protect Allison's friends from it she made a promise and she is going to keep it. There was a lacrosse game going on when the beast came out of hidden and so did Artemis see she kept who she really was.

Flashback

Artemis was one of the best hunters there was she worked with the Argents they showed her some moves and she showed them some of hers. When she was on the job one day she was hunting a werewolf but in the end, she killed a human that got in the way when she shot an arrow now she didn't mean to it just happened. So, in the end, she stopped being a Hunter for many years.

End of flashback

When Artemis showed up at the school she went to her trunk and pulled out her bow with many arrows and went inside the school. When in the school she saw the kids running in the opposite direction she was going when all of the kids left there Artemis saw the beast. The beast growled at her so Artemis went up to it but that was a bad idea the beast slammed her into a set of lockers then the beast ran off so Artemis took off after it.

In the library where Scott was with other kids he saw that they all looked scared When he heard the beast coming he looked at everyone and said "get everyone to higher ground" when the beast came into the library Scott went full werewolf on the beast but what Scott didn't know is that Artemis was right behind the beast. When the beast knocked Scott down Artemis started to shoot arrows in the beast back to distract it when she did Scott's pack came in and attacked the beast.

Then the beast jumped out the window Artemis went over to Scott to help him up but then he said "Allison" "No I'm a friend of hers my name is Artemis now you get your pack out of here this Beast is bad news" Artemis was about to leave but Scott said something to her that change her mind. "You can help us can't you," he said "No the reason I'm doing this is because I promise Allison that I would protect her friends," Artemis said then she left.