I have read a few reviews here and there - mostly here, on Goodreads - and I have to say some people really don't know the definition of anticlimactic.
This story is anything but.
"The Last Flight of the Cassandra" is basically a setup for a tabletop RPG set in the Expanse universe, but in itself, this novella is what I would consider a hidden gem of the Expanse.
Possibly the least-read story in the series (and also considered non-canon, I hear), I couldn't help but love it from the beginning to the end.
It introduces brand-new characters, as they never appeared in other Expanse-related work, and builds up suspense, unraveling a mystery while ending on somewhat of a cliffhanger.
There are a lot of questions left, but I guess they are left to the imagination or to a tabletop gaming session.
All in all, I love a story that challenges the reader, and this one was definitely it.