Jon and Seiji's Monstrously Macabre Predicament

Jon & Mack's Cases #12

by A.J. Sherwood

Is Jon happy to finally meet Seiji, the awesome Chaos Magician he’s been hearing about? Absolutely.

Is he happy he needs to call Seiji in for a case involving hundreds of portals dripping blood he can read when he shouldn’t be able to? Absolutely not.

Will lots of lives be lost to the living sacrifice altar if they don’t find the perpetrator quickly? Beyond a doubt.

Do they know how to go about saving those people? Here’s hoping.


Halloween special, macabre case, cannibalism, you know its bad when Jon calls a Chaos Magician in for backup, Seiji and Jon finally meet, Seiji explains Jon, Jon is thankful, apprentices, portals, not all psychics are good psychics, Jon does not like this timeline, Seiji doesn’t either, Donovan has left the building, Lachlan’s just sad he doesn’t get to stab anything, this case happens after Seiji x Lachlan story, Donovan prefers actual haunted houses over this


Police Procedural, Mystery, Contemporary Fantasy, Bonded Lovers, MM Romance, Psychic Powers, Horror, Paranormal

Genres: M M Romance, Fantasy, Romance, Supernatural, LGBT, Magic, Novella

137 pages, Kindle Edition

First published October 30, 2026

About the author

AJ Sherwood believes in happily ever afters, magic, dragons, good men, and dark chocolate. She often dreams at night of delectable men doing sexy things with each other. In between writing multiple books (often at the same time) she pets her cats, plays with her dogs, and attempts insane things like aerial yoga.

She currently resides in Tennessee with aforementioned cats, dogs, and her editor/best friend/sister/partner in crime.

Reviews

[Cynthia M Brow · Rating 5 out of 5]

Jon and Seiji's Monstrously Macabre Predicament is part of the Jon's Mysteries world. I love any book that has Jon and Donavan but when you throw in Seiji and Lachlan it's double the fun. I read this short story in one sitting because it was so good. I loved watching Jon and Seiji meet for the first time. The plot was perfect for a Halloween release. I can't wait for Seiji and Lachlan's series now. I would definitely recommend this book and anything else AJ Sherwood or one of their other pen names writes as 5 star reads.

[Beanzie · Rating 5 out of 5]

I've been in such a reading slump with life getting in the way but when I saw this pop up in my recommended books, I knew I had found the light at the end of the tunnel. I love the Jon case file series and everything that has stem from it. As usual Jon and Don are working cases way above their pay rate and now with Seiji on board. Just when I thought I had learned everything from this world, here comes some more crazy. It was short and sweet and didn't feel lacking in anyway. I love how Seiji was able to help Jon with his out of control psysic ability, even if it was just a tiny bit. I'm always sad when it's over cause I always want more. I can't wait to read Seiji's and his beasty hunter love story soon to come. 5/5 stars.

[Zoe · Rating 5 out of 5]

Fantastic Crossover!

I always love seeing more of Jon and Don and of course it was great to see Seiji and Lachlan again! This novella was not as spooky as I was anticipating and I am very glad for that! But it was still a great time seeing them all work together to catch the bad guys and I’m very happy that they knew who to call because things definitely did not sound good. I am also very happy about how things are turning out for Jon with all the new helpful friends he’s made and I hope that we will get to see more of everyone in this universe hopefully in a less stressful situation and with everyone doing better than when the series started!

[Darcy · Rating 3 out of 5]

It was fun to see Jon and Seiji met and how great they got along, but man...the case they worked on was so gruesome and gross! I loved that right away Jon knew he was in over his head and that they needed to call Seiji in to help. Once Seiji got there it was funny how both Jon and he were startled and impressed by the other. Nice that Seiji realized he might be able to help Jon with how his magic worked and better that at the end, after all the bad guys were dealt with, they did just that. Even getting the younger crew in on things too. It will be interesting to see how this fix for Jon and Abby helps them out going forward.

[Sarah A · Rating 5 out of 5]

Chaos Magician meet Powerful Reader

Séji meet Jon.

A nice novella to bring the new characters of Lachlan and Seji into Jon and Donovan’s universe and follow up on the apprentices.
A nasty story - cannibals, men lacking any emotion or self-awareness or empathy.

Don’t read whilst eating if sensitive.
Also Tw domestic abuse, coma victims, physician abuse.

Good to see the characters meet and evolve.

[Golden Child · Rating 5 out of 5]

Jon & Donovan/Seiji & Lachlan

Finally these two meet. Jon has a case that he knows he needs a chaos magician for so he immediately calls in Seiji who he’s heard of but has never met. Seiji, missing Lachlan immediately jumps in the car to go help. Lachlan is right behind him. A gruesome case takes the crew a bit to unravel but together they get it done. Looking forward to more from this crew.

[Jenette · Rating 2.5 out of 5]

The plot of this this one worked a lot better than some previous instalments in this universe simply because it wasn’t an overfilled chaotic mess of too many characters (actually, there were still a few too many) and too much happening at once. I think for me, I can read Jon and Donovan but everyone else is just too much. (Also exactly the same).

I did lop off half a star for the weird Limiter nonsense that came out of nowhere.

[Lee Hall · Rating 5 out of 5]

Jon and his new friend Seiji

Jon is embroiled in another case! This time they are way out of their depth and have to call in a chaos magician, Seiji. They have been wanting to meet for a while and this is a great opportunity to do so. Seiji and Lachlan join Jon and Donovan in a hair raising case that tests both to their limits.
Another wonderful story that I look forward to reading again! Highly Recommended

[Brendan Bohl · Rating 5 out of 5]

Delightfully Macabre Time!!

I love Jon and Donavon and Seiji and Lachlan!! Wicked good time all around!! Please more Jon and Mack Stories!! Looking forward to seeing more of Seiji and Lachlan!
The guys are back again, hunting evil, destroying portals and dodging the Ick! Good food, good friends and plenty of love makes it all go round.
Love, love, love!! ❤️

[Amanda · Rating 5 out of 5]

Love this Halloween treat!

I adore this expanding world and am always thrilled with a new entry. It’s great to get a glimpse of the apprentices and see hoe Seiji and Lachlan have settled. The new situation is truly twisted and deserving of the big guns. Jon is still my favorite, but Seiji is a close second.

[T.A · Rating 5 out of 5]

House of Horrors

Seiji answers Jon’s called for help regarding a house with blood. Lachlan mets up with him there.
Seiji also finds a way to help Jon and Abby with their psychic abilities.

I loved the book.

[sharen Fruth · Rating 5 out of 5]

Terrific

Book was as good as the first one and all of them were terrific!! Love these stories but read them in order or your lost!! Read about Mack and Brandon as well! It will be less confusing!!

[Samantha Kelling · Rating 5 out of 5]

Fun, disturbing and sweet

Wonderful continuation of the series! It's always fun to see the side characters and have their story too. There were some very disturbing scenes, just to warn people, but it was still an excellent read!

[Lois · Rating 4.75 out of 5]

I love all the crazy characters in the Jon and Mack books and this one was no different. The crazy was cranked up to 11 and Jon and Seiji were in for a rough ride. This was fun in a truly macabre way with cannibals, blood magic and a sprinkling of psychopathy. I loved it

[Kati Darling · Rating 5 out of 5]

Excellent Halloween read

Loved seeing the world expanded
Seeing new abilities and takes on situations
Love the relationship s between everyone
Looking forward to seeing what happens next

[Raven and Chris · Rating 5 out of 5]

Jon and Seiji!

I love Jon and Donovan so much. Seiji is a much newer character here but equally as lovable. Jon was my first intro to AJ Sherwood’s work and he will always be one of my favorites. They have a truly awful case to solve with this one!

[andrea moran · Rating 5 out of 5]

Jon’s mysteries

I absolutely adore almost everything in this shared world and was glad that this latest lived up to the others after that weird dreamscape one! Love the banter and found family feel of these stories. Can’t wait for Seiji and Lachlans story next

[Jessica Gorgen · Rating 4 out of 5]

really liked it

I really liked this book. 4 stars for rating, 0 for spice. This was a doozy of a case, lots of ick and wondering how humans can be so evil. But it was well done, and nice to see Jon and Seiji meet for the first time.

[ghislaine belair · Rating 5 out of 5]

Excellent. I love the characters very much. I enjoyed this story also.

[Bookbeard · Rating 4 out of 5]

story line: ****
main characters: *****
side characters: ****
world building: ***
editing: *****

[Jai Oni · Rating 4 out of 5]

Rating: ⭐️⭐️⭐️⭐️
Enjoyment: ❤️❤️❤️❤️❤️

[Demian Grimm · Rating 5 out of 5]

I was able to read this early via the author's Patreon.

[Lisa · Rating 5 out of 5]

We were introduced to Seiji in the previous book and in this tale Jon calls him in after a gruesome scene and one that calls for Seiji's expertise.
A suitable horror tale for Halloween.

[Sniege · Rating 5 out of 5]

Perfectly Halloween coded novella, and we got to know little bit more about Seiji