What worked: All of it! I love short stories analogies but especially ones that have tales from characters I loved in a series. Each story is like a backstory of the whys behind the character's motivations. Readers also see the flaws and wounds. The end result is you have a very satisfying collection.
Here's a few of the tales:
THE KEEPER shows readers Scarlet's grandmother Michelle and what lead up to her part of Cinder's transformation from a burned victim to a cyborg. This short story fleshes out Michelle more as I felt she was more of a secondary character in the novel. There's also some major reveals on Scarlet that I won't post here but let's just say it all starts to make sense.
THE QUEEN'S ARMY: This one tale has to be one of my favorites as it shows how Wolf transformed from a poor boy on the outskirts of Lunar to the fierce soldier. Readers also see the start of brother rivalry.
GLITCHES is the heartbreaking tale of when Cinder first meets her adoptive family in New Beijing. We also see an earlier Iko. The emotions of a young newly transformed Cinder of wanting so much to belong to when her new 'step-father' is just diagnosed with letumosis will tear at your hearts.
SOMETHING OLD, SOMETHING NEW is my favorite story as it ties in all the books to a very satisfying conclusion with one not too obvious reveal at the end.
There's also a special bonus excerpt from her standalone novel, HEARTLESS.
A very satisfying peek into the backstories of the characters from the Lunar Chronicles.