Agatha initially agrees to manipulate Billy into doing just that, then has a last-minute change of heart. She kisses Rio/Death and thereby embraces her fate, sacrificing herself so Billy can live. From the start she had a soft spot for the teen, accompanied by references to her long-dead son. The backstory is quite moving and key to Agatha’s unexpected change of heart. Her son’s fate was revealed in the finale. Death came for him when Agatha was in labor but agreed to grant her “time.” How much time? Six or seven years, during which mother and son bonded and wandered from village to village, with Agatha occasionally killing more covens to absorb their power. But Death did not forget, and with Nicky (Abel Lysenko) gone, Agatha indulged all her worst impulses.

Which brings us to the Big Twist: Agatha and her son made up the ballad of the Witches’ Road, singing it in local taverns and slowly building up the legend. The Witches’ Road never existed. Agatha used the legend over centuries to lure witches into a trap to steal their powers. That was her intention at the start of the series, too, except this time—a portal opened. Billy, it seems, inherited Wanda’s ability to warp and shape reality, even subconsciously. He wanted the road to be real and so it was.

The reveal is skillfully done and ties everything up in a nice satisfying bow, with one exception. The writers just couldn’t let Agatha go completely; she returns as a ghost and joins Billy on his search for his brother Tommy. That’s a creative choice that leaves the door open for a second season, and I strongly suspect we’ll get one. But Ghost Agatha will be a tough plot point to crack. And it rather undercuts the pivotal moment of Agatha’s sacrifice—actually doing something that doesn’t directly benefit herself. On the whole, though, Agatha All Along is marvelously entertaining, binge-able fun with just enough emotional resonance and heartbreak to add some depth.

All episodes of Agatha All Along are now streaming on Disney+.