The actress tells THR that Andrea “becomes more of a sharpshooter and is really trying to make amends for not necessarily having it all together.”

Andrea’s mistaking Daryl for a walker on AMC’s The Walking Dead will change everything for the woman who, up until recently, was still very much unhappy to be alive.

On last week’s episode, titled “Chupacabra,” Andrea (Laurie Holden) took a step toward becoming the fierce sharpshooter depicted in the Robert Kirkman comic book series on which the show is based on when, in an effort to protect the group, she nearly shoots Daryl (Norman Reedus) from a couple hundred feet away after mistaking him for a walker.

“What’s so mortifying to Andrea is that she’s so eager and anxious that she finally has her opportunity to prove to herself and everybody in the camp that she’s able and a valuable part of the community and she blows it on such a massive level,” Holden tells The Hollywood Reporter. “She almost kills someone that she cares about and is loved by all.”

Up until this point, Andrea has been a woman on suicide watch, unhappy that Dale (Jeffrey DeMunn) wouldn’t go along with her death wish at the CDC at the end of Season 1. As part of that watch, the group has stripped Andrea of her gun and forced her to address her unease, making the shooting that much more of a game-changer.

Holden says Andrea’s near-miss – the bullet grazes Daryl’s head, leaving him with a non-fatal injury – and accompanying shame will “light a fire” under her to be better and be more responsible when it comes to protecting the rag-tag group of survivors that she’s come to care about.

“It propels Andrea forward to try and be the best person she could be,” Holden says of her “flawed” character. “You see in the episodes to come that Andrea becomes more of a sharpshooter and is really trying to make amends for not necessarily having it all together.”

Having already questioned Shane (Jon Bernthal) about the robotic and almost flippant way in which he kills zombies – he says he uses his law enforcement approach of flipping a switch – Holden says Andrea turns to him again in her push to evolve from panicking during the throng of close calls she’s already had with the undead.

“He gives her the school of tough love and it’s the best thing that ever happened to her because it everything changes,” Holden says. “When there are attacks by walkers, she has more of a Zen approach to it and doesn’t let her panic and fear take over; she really embraces her inner strength and goes into warrior mode.”

In the process, Shane will become a “real mentor” for Andrea, who becomes an eager and avid pupil. “He takes me under his wing and becomes a dear friend,” she teases of their burgeoning relationship, noting that their outsider status isn’t the only thing they have in common.

“He’s been beaten up in this apocalypse and his heart has been broken, so it’s probably nice for him to have somebody look to him and think he’s pretty terrific and think he’s an admirable leader,” Holden notes. “Andrea and Shane are buddies who found each other in war.”

After already considering splitting from the group with Shane, Holden says the duo’s increased time together may create a deeper rift in her already complicated relationship with Dale (which in the Image comic series blossoms into a romantic relationship).

“Dale loves Andrea but he’s kind and overprotective and sometimes it’s too much,” Holden warns. “As Andrea said in the first episode this season, ‘He’s not my husband, he’s not my father.’ Andrea is a free agent and if she wants to spend time with somebody else she has the right to that but that doesn’t mean he’s not going to be bent out of shape or upset by it. If he doesn’t approve, there’s not much Andrea can do about that.”

With Andrea already pondering leaving the group with Shane and aware of his romantic history with Lori (Sarah Wayne Callies), Holden says that will be water under the bridge when it comes to her allegiances within the gang.

“It’s all petty,” she says. “It’s about survival and looking at this alpha male who has fallen in love with this woman and Andrea doesn’t know what the complication is. What she does know is Shane could potentially leave and that’s a problem. If he leaves, Andrea wants to align herself with him. Anything that’s going on in his romantic life is not really of any concern for her.”