Some of the more tear-inducing moments from the October Daye series include:

* The premise of the first book and the overall series: October Daye is turned into a fish for 14 years with everyone thinking she's dead and when she returns, her entire mortal life is gone. Her business was sold to cover her debts, her fiancé married another woman, and her daughter grew up calling said woman "Mom" with both believing that Toby simply abandoned them.
** And because neither of them know about the Fae, Toby ''can't'' outright explain what happened; the first chapter picks up six months after Daye escaped the koi pond she was imprisioned in and shown she's cut off all contact with the Fae community blaming them for what happened. Toby spends a good selection of the books functionally depressed.
** [[FromBadToWorse Made all the worse]] with the reveal that Miranda, the woman Cliff married and raised Gillian, is [[spoiler: Toby's grandmother and had been poisoning their relationship to alienate October. Partially because she legitimately believed Toby abandon them and partially because she's come to love Gillian as her own child.]]
** [[spoiler: Then after a few years, Gillian finally learns the truth: only to reject Toby ''again'' after being kidnapped several times and asserts that Miranda is her "real" mother. Thankfully the short story after Toby's wedding to Tybalt sees her agreeing to try to mend bridges with her biological mom.]]
* [[spoiler: Quentin having to give up his first love in order to allow her to live a sane and peaceful life after what Blind Michael did to her.]]
* From ''Late Eclipses:''[[spoiler: Lily's death. She's been a presence since the first book, quietly in Toby's corner from the beginning, helping and guiding as much as she could... and then she dies in Toby's arms, and there's nothing the changeling can do about it. She's the first established and recurrent character to pass away, marking a point of inflexion for the series.]]
* And in ''One Salt Sea'': [[spoiler: Toby having to give her daughter Gillian the Changeling's Choice, and because of past history, which choice Gillian makes]].
** To elaborate a little... [[spoiler:This is the first time Gillian appears in the story since the first chapter, but she's been more or less present throughout the story thanks to constantly being in her mother's thoughts. Gillian has been kidnapped, and while Toby manages to find her before too much harm is done, a stray elf-shot forces Toby to give her daughter the Changeling's Choice to save her life. All Gillian wants is to go back to before Toby went missing, but that's not an option.]]
* Also from ''One Salt Sea'' [[spoiler:The Luidaeg takes Toby to the selkie colony in the middle of Connor's funeral, revealing the truth behind their existence, of how the Luidaeg was mother to the Roane, how most of them were killed for the skins by the first Selkies in an attempt to become inmortal, but doomed their descendants to always bear the skins until the day they could make things right. She hates the Selkies for killing her children and grandchildren, but also loves them for keeping their magic alive.]]
* "In Sea Salt Tears": Liz finally getting the opportunity to get a skin and go from kin to true selkie -- but at the cost of her lover [[spoiler: who turns out to have been the Luidaeg]].
* Re-reading ''An Artificial Night'' in the light of ''One Salt Sea'' - the Luidaeg [[spoiler: telling Toby to get rid of the children, claiming she [[BlatantLies can't stand kids.]] ]]
** It gets worse! The Luidaeg ''can't lie,'' which means that what she tells Toby is actually true -- until ''A Killing Frost,'' when it's mentioned that [[spoiler: her geas won't let her say that she doesn't like kids anymore, now that the Roane are back.]]
* The ending of ''The Brightest Fell'', all round. Toby completes her quest and saves the day, but everyone is horrifically traumatized from Amandine's actions, [[spoiler: August is free of her curse but has lost her father to it, and Simon has regressed to the cruel man from book 1 because the curse doesn't allow him to remember any of his progress toward atonement.]]
* Why is Tybalt avoiding Toby in ''Night and Silence''? She thinks it's because he can't help but blame her for Amandine's actions, since he'd never have been in the line of fire if he wasn't dating her. It's worse: [[spoiler: he blames ''himself'' for being traumatized, thinking he's weak and broken and Toby won't want him anymore.]]
* ''A Killing Frost'' is an extended one for Simon. [[spoiler: Turns out Eira had her hooks in him far longer than anyone knew. It didn't start with finding August, it started with offering himself up to keep her from mind-controlling Patrick away from Dianda, and then it only got worse--and he ''knew'' how awful she is, but his abandonment issues are so bad that he considered being reliably abused and manipulated better than being alone.]]
* ''When Sorrows Come'' begins with Quentin making a trade for temporary new identity in order to attend Toby's wedding because after all these years he understands her life well enough to know someone's going to try and kill her. This leads him to confessing that [[ParentalSubstitute Toby's his mom]] stating its been her in his life after being placed into blind fosterage seven years ago. In this moment he's not a squire wanting to protect his knight but a son whose fears for his parent's safety and this confession leads them to hugging and cry.
* The ending of [[spoiler:''Be the Serpent'', portraying Titania's revenge on Toby. Just as she tells Tybalt she's pregnant, she vanishes, waking up living a different life in which she's subservient to August and still living at Amandine's tower, with a single throwaway line implying Tybalt is out there trying to get her back.]]
** The acompanying novella also doesn't pull any punches, the day the Luidaeg lost her family, and how she came to be bound by Titania's geas.
** [[spoiler:Jessica's death, made worse by the fact that it was (technically) done by her own mother. Worse, several characters mention how she had been recovering from her time in Blind Michael's hands, with Toby mentioning how she still wanted to work with horses as a vet, even though she was scared of them.]]