What Happens to Neyrelle and Lorath After Diablo 4? (Story Spoilers)

wowhead.com:

What happens to Neyrelle and Lorath Nahr after the events of Diablo 4? Where do they go? The newest book release, «Diablo: Book of Lorath», answers these questions and tells us what happens after the conclusion of Diablo 4's story! Diablo: Book of Lorath on AmazonVenture further at your own risk, Mortal. Below, you will find spoilers for the story of Diablo 4, as well as speculation citing resources from the outside book, Diablo: Book of Lorath. If you don't wish to spoil the story for yourself, it is highly advised that you do not continue! At the conclusion of Diablo 4's story campaign, we're left with a sense of dread and more questions than answers: Donan is gone, Lorath is the last of the Horadrim, and Neyrelle, who bears the Soulstone containing Mephisto, Lord of Hatred and eldest of the Prime Evils, has fled to begin her own journey in an effort to defeat Hatred once and for all. In the epilogue, we are treated to a brief showing of her journey; from the snowy mountains of Kyovashad to eventually sailing off across what we can assume is the Twin Seas, Neyrelle is shadowed by a familiar Bloody Wolf the whole time — Mephisto, ever present in the Soulstone, haunting her every step.Diablo 4's Epilogue cutscene. While this cliffhanger has left players yearning for more information on the story of Diablo 4, it seems that The Book of Lorath contains the continuation of Neyrelle's and Lorath's story through letters between the two — while Lorath pursues her across the known world, Neyrelle leaves behind correspondence to her mentor and friend, and Lorath races against time to find her before Mephisto's corruption can truly take hold.

The Book of Lorath begins with a sort of formal type