Game of Thrones, which returns for its final season on Sunday, has always been obsessed with the question of power—how you get it, how you wield it, how you hold onto it. And even in the violent patriarchy of Thrones, which kind of makes our own medieval times look like a Renaissance faire, a tremendous amount of that power is wielded by mothers.

Because Westeros is a primogeniture society where heirs—and daughters who marry heirs in order to cement alliances—are essential, having a child is one of the central ways women gain power. The way mothers end up using that power, and how those decisions reverberate for them and their children, has been a riveting and troubling theme for seven seasons because no amount of power, no willingness to do terrible things, actually keeps anyone’s children safe. Thrones amplifies the central tension of parenthood, which is that children make you both stronger and weaker. There’s the strength of knowing you’d do anything to protect your child; there’s the vulnerability of knowing that no matter what, you cannot guarantee their safety.

When the show begins, Cersei Lannister is the queen of Westeros, married to King Robert Baratheon, and the most powerful woman in the Seven Kingdoms. But that power is precarious, because her children, passed off as the true heirs to Robert’s throne, are actually the product of an affair with her twin brother, Jaime. In cuckolding the king, Cersei creates a huge risk for the ones she loves the most—her children would be killed if the truth came out—but the deception sharpens her sense of danger, making her ruthless and brutal. She has Robert killed, then outmaneuvers Ned Stark, the hand of the king, and has him beheaded.

Motherhood makes women (more) vulnerable, but the focus on their families allows them, or gives them an excuse, to be utterly merciless. As Olenna Tyrell, the Queen of Thorns and de facto ruler of House Tyrell—a powerful family that evolves from a Lannister ally to a bitter enemy—puts it to Jaime: “I did unspeakable things to protect my family. Or watched them being done on my orders. I never lost a night’s sleep over them. But your sister has done things I wasn’t capable of imagining.”

And Olenna has imagined a lot. When her granddaughter Margaery is betrothed to Cersei’s son Joffrey, who becomes king after Robert dies, Olenna goes on a quiet fact-finding mission about her future grandson-in-law. The results are so monstrous she arranges to have him poisoned at his own wedding. For a while, the move pays off—Margaery becomes engaged to Cersei’s younger son Tommen, the new king, who has the benefit of being sweet, pliable, and not a sociopath.

But as with all things in Thrones, this act ricochets in unanticipated ways. Cersei goes into full apocalyptic mode, battling Margaery for control of Tommen, and when she loses that battle she blows up the Sept of Baelor, killing Margaery, Margaery’s brother and father, and about a thousand other people. This act, meant in her mind to save her last child and preserve her influence over him, results in Tommen’s suicide. With nothing left to lose, Cersei takes the Iron Throne for herself.

If this is some hideous comment about work-life balance, I’m not amused, but I don’t think that’s the point. Mothers on Thrones go to any length to keep their children safe, including murdering other people’s children. But in the end, they face what all parents face: the knowledge that nothing you do can fully protect your child from the world.

As the final season opens, the two most powerful characters on the show are Cersei and Daenerys Targaryen, the “Mother of Dragons,” who is invading Westeros to regain her birthright. As different as they are as rulers, Cersei and Dany have one uncomfortable similarity—the path to power for both of them is littered with loss. Cersei’s three children are dead (her daughter, Myrcella, is killed before Tommen’s suicide), and Daenerys becomes the Mother of Dragons by hatching three dragon eggs in the pyre that burned her dead husband—after losing both him and their newborn son.

In a winner-take-all system like Westeros’, power often comes at an unspeakable cost. It isn’t an accident that Gilly, the wildling who seeks refuge with Sam Tarly of the Night’s Watch, is the only mother left in the show’s cast of characters who hasn’t lost a child. She’s brave and resourceful, of course; she also has the least political power and is removed from the central action in King’s Landing.

There’s also a subtler conclusion to draw. Cersei and Daenerys have both shown they can survive unthinkable loss, and that gives them legitimacy as leaders, a price men in power are not asked to pay. And even when they are—Jaime has, no less than Cersei, lost all three of his children—it’s not treated as crucial to their characters. It reminded me of the research suggesting a disproportionate number of female politicians are breast cancer survivorsbecause it confers respect on a level equivalent to a war wound. It seems that in both Westeros and our own society, the bar for women to reach leadership positions is disturbingly high.

Game of Thrones’ showrunners have shot multiple finales for the series, so it’s anyone’s guess how it will end. What we do know is that Cersei is pregnant again and—with the disclaimer that trying to predict what happens on Thrones is usually a fool’s game—the show has heavily foreshadowed a pregnancy for Daenerys. Perhaps the question of how to wield power in order to keep your family safe will finally be answered.

Daenerys has taken her army up north to fight the white walkers, who threaten all of Westeros. Cersei has given her word that she will help them, but she plans to betray them instead and finish off whatever remnants are left after the battle. Daenerys represents what you could refer to as the geopolitical stability camp: You cannot have safety and prosperity for your own house if you don’t try to ensure it for everyone. Cersei’s model is Lannisters First: She doesn’t care if it all burns down as long as her family survives.

Cersei ran this play before, and it didn’t end well for her. But she won’t change. Her love for her children is the one pure, incorruptible thing about her, the engine of her ruthlessness and a deep vulnerability. She’s not alone. Practically every mother on Thrones does things to protect their children—like Catelyn Stark taking Tyrion Lannister prisoner to safeguard Bran (mistakenly), or Olenna poisoning Joffrey, or Ellaria Sand of Dorne plotting to overthrow Cersei—that end in catastrophe. Escalation usually does. In an odd way, Thrones is like a bleak extended metaphor for overparenting: No one, no matter how powerful, can shape the world to fit their child. The more you try, the more it ends in ashes.