I'm glad you've submitted another story to the OPR jam! I hope this has and will continue to be a good experience for you.
I liked the twist ending - you did an excellent job misdirecting the reader as to what's coming, and as a result the real twist lands with a very tangible impact; well done. There's some ambiguity over timing in the setup - Aithne wakes up 'the next morning' and finds a note from Lexer that's been written 'days ago'; maybe something that didn't get caught in an editorial change?
It took me some time to learn this as a new writer, but when you tag dialogue, you don't need anything other than 'said'. 'Proclaimed', 'begged', even 'asked' are all obvious from what the character is saying. Eliminating anything but 'said' makes your tags "invisible" and helps the dialogue flow more smoothly.
Overall this was a nicely ominous piece with a clever twist, and I hope to read more entertainingly dark stories from you in the future!