so I started rereading GtN (as one does) and was struck by this passage where from the very beginning of the book, Gideon positions herself as more important to Harrow than the Locked Tomb:

“So, here’s the thing, your Lady would set the Locked Tomb on fire if it meant I’d never see another sky,” Gideon said, looking up. “Your Lady would stone cold eat a baby if it meant she got to lock me up infinitely. Your Lady would slather burning turds on the great-aunts if she thought it would ruin my day. Your Lady is the nastiest b—”ALT

cut to the pool scene and Gideon learns that not only does Harrow love the corpse of the Locked Tomb, but that the corpse of the Locked Tomb was, in all her silent sleep, able to convince Harrow to live in a way Gideon’s (loud, active, constant) existance in her life was never able to

“Nav, when I saw her face I decided I wanted to live. I decided to live forever just in case she ever woke up.” Her voice had the quality of someone in a long dream. She stared through Gideon without looking at her, and Gideon gently took her hands away from Harrow’s jaw.ALT
Gideon’s brain moved and broke against itself like the tiny wavelets they had left, the water lurching restlessly from side to side, until it came to a final conclusion.ALT

and I think that is really, like, when Gideon truly starts her sort of… backslide wrt her perception of her relationship with Harrow – like, at this point in the story in the pool, she’s already well along in her corruption arc into the “Perfect Cavalier”. BUT like, we know from being inside Harrow’s head that Harrow would break herself and her duty in order to hold onto Gideon. she would & she did!!!! which is!!! something that Gideon KNOWS at the beginning of GtN but then forgets/is convinced out of, entierly unintentionally, but to the point where by the time she comes back in HtN she has a totally reversed perception of how Harrow feels. leading to, of course, this:

said. “She’s in love with the refrigerated museum piece in the Locked Tomb. You should’ve seen the look she had on when she told me about this ice-lolly bimbo. I knew the moment I saw it. I never made her look like that … She can’t love me, even if I’d wanted her to. She can’t love you. She can’t even try.”ALT

anyway.