There is rarely a single scene to point at. It is the call you both forget to make, the joke that stops landing, the silence that gradually stops feeling like a wound and starts feeling like the weather. By the time you name it, most of the leaving has quietly already happened.
The cruelty is how reasonable it all seems from inside. Nobody did anything unforgivable; you simply stopped choosing each other in a thousand small daily ways, and the sum of those omissions turned out to be an ending.
The music thins and cools, the sound of a thing gently losing its grip. Space opening between the parts, warmth leaking out of the chords, a fade that arrives so slowly you barely notice the room going quiet.
Here the series begins its long decline, tender and sad. Play it when nothing is wrong, exactly, and nothing is quite right either.