Buffy the Vampire Slayer’s Dawn Summers Is TV’s Most Important Sister

After leaving high school behind in the season 3 finale, Buffy the Vampire Slayer struggled to find its footing in young adulthood. Season 4 was an epic mix of highs and lows, with each episode being a toss-up between a series-defining masterpiece and a well-intended misfire. In the wake of that often disappointing 22-episode run, it was clear that Buffy needed a change of pace. By perfectly blending the show’s signature supernatural elements with relatable, grounded drama, season 5 is brave, moving, and masterful – thanks, in no small part, to the introduction of Buffy’s (Sarah Michelle Gellar) brand-new little sister Dawn, played by Michelle Trachtenberg, who tragically passed away on Feb. 26, 2025.

In what remains one of the best teen drama twists of all time, season 5’s opening episode drops a bombshell before a quick cut-to-black: the young girl briefly shown in Buffy’s room is, according to their mother, her little sister—despite never being part of the series prior to this moment. As the season continues on, Buffy eventually learns that Dawn was created by a group of monks, transformed from a magical key into a person that Buffy herself would ultimately die to protect from an angry god. While this premise is as harebrained as it gets (and par for the course in the series’ supernatural wheelhouse), Dawn’s evolution from annoying little sister to beloved pillar of the show all circles back to the brilliant writing elevated by Trachtenberg’s vulnerable and moving performance. 

Dawn herself could have easily devolved into nothing more than a plot device. Her presence in the fifth season’s story is straightforward and often predictable, and, in less capable hands, it’s easy to see how one-note this key-turned-sister could’ve been. But from her very first full episode on the show (titled “Real Me,” season 5 episode 2), Trachtenberg imbues her with a tangibility that is only matched by Gellar’s early work on the series as Buffy herself. 

There’s a gentle touch behind every move Dawn makes, where her charming, troublemaking streak blends with her heartbreaking, grounded fear layered with a heavy dose of supernatural symbolism. Dawn questions whether or not she’s a real person deserving of love, mirroring the fears of many teenagers as they try to develop into themselves. Dawn acts out when Buffy’s larger-than-life stakes overshadow her teenage drama, injecting an even stronger inferiority complex against Buffy’s godly position within her family and friend group. 

In one of Trachtenberg’s greatest moments on Buffy, Dawn and Buffy regroup after a fight with the season’s Big Bad, and Buffy asks if Dawn is alright. Dawn asks why Buffy cares, she’s not really her sister, after all. She’s just an object that a group of monks made flesh, why should Buffy concern herself with her feelings? Who’s to say she even has them? But when Buffy takes her own blood and clasps Dawn’s bloody hand within her own, it’s clear that these two women are bound for life. Even without the Summers blood running through her veins, Buffy loves Dawn, and no amount of cosmic intervention could change that. 

While Gellar is often the focal point of the scene, Trachtenberg gives such a stunning performance, even after her lines have finished. You can see as she puts up her walls, preemptively shutting Buffy out before her sister can hurt her by insisting that she’s not a person at all. Those walls slowly come down throughout Buffy’s heartfelt speech, genuine love and surprise clouding Trachtenberg’s wide, blue eyes. When Buffy finally hugs her, her face fully collapses, crying into her sister’s shoulder as she finally admits that she’s just a scared kid, facing problems and obstacles far beyond her reach.