Salt & Stone picks up right where Fire & Flood left off. The remaining competitors (64 from the original 122),  are recovering at base camp, waiting for the next leg of their race. Tella, Harper, Guy, Olivia, Jaxon and Braun have formed close bonds, and intend to stay together until the end if possible. All too soon, the next leg of their journey, crossing the sea, begins. 
I'm not usually able to say this, but I enjoyed book two even more than book one. Tella asserts her independence, which, while increasing the tension between her and Guy, is necessary for her development as a believable character. There are some deaths, a reunion, a new character, and some great twists, some predictable and one that blindsided me. Towards the end of the race, there are three challenges that must be met in order to advance to the finish. If you've read The Testing, Independent Study and Graduation Day by Joelle Charbonneau, the feel of Tella's challenges is very similar to what Cia experienced. If you haven't read the series, you might like to consider it. 
The ending leaves some unanswered questions, and I'd really like there to be a third book, but Scholastic has only bought the rights to the first two, so there might not be a third. That would truly be disappointing. Guess I'll have to get more people reading these two books! :-)
Definitely stock this on your middle school library shelf, but be warned that it does contain quite a bit of violence. If your readers can handle the Hunger Games and Divergent violence, they can handle this. Tella is morally strong so she does the right thing, even when survival instinct says to do the opposite.

All I have to say to myself in order to remember this book is Hunger Games meets Pokemon in a Survivor setting. This is not a new book. It was published in 2013, but since I just finished book two, I thought I'd review them together. 
Tella Holloway has a brother suffering from an undiagnosed and seemingly incurable disease, and her parents have moved the family to the middle of nowhere in the hopes that fresh air might help, or at least that's the story Tella was given.
Understandably, she feels hopeless so when a mysterious invitation appears, advising her that she can compete in the Brimstone Bleed to potentially win a cure for her brother's ailment, she's all in. 
Before the race begins, each Contender has a scavenger hunt opportunity in a barn to find a Pandora egg which will hatch to an individually genetically mutated creature designed to increase the Contender's chances of success. If you have any experience with the affection that fictional cartoon character Ash, a Pokemon handler, has for his creatures - that's what I imagine most Contenders feel for their Pandora. I really enjoyed the crazy modifications to the animals. Scott clearly has a vivid imagination.
The Bleed takes about three months and spans four ecosystems; jungle, desert, sea and mountain. The single winner gets a Cure for their loved one. Alliances have started to form, and the rugged environments and the not knowing who you can trust are the parts that made me think of Survivor.
This book really left me wanting more since it ended in the middle of the race; they've only crossed the jungle and the desert. I think it will be extremely popular among middle school readers who like adventure, survival violence and even a little romance.

This is a surprisingly scary tale featuring two orphans who come to work at a house in the middle of nowhere. The family they work for is acting strangely and eventually the children figure out that the family's very essence is being sapped by the night gardener who is using the sweat of their bad dreams to nourish a tree that grows near the house. The children, Molly and Kip, initially escape, but then realize they have to go back and save the family from the night gardener and the tree.

Madeline Whittier has SCID, which is an autoimmune disease where she can't go outside because she will react to everything and die. Think about the boy in the bubble movie, and that's what I'm talking about. Madeline is a strong character who doesn't whine about the unfairness of her life. She has come to accept her existence as it is UNTIL Olly moves next door and they become friends and more. This book is more mature than I expected so I recommend it for students in grade eight up. If they've read The Fault in our Stars, they can read this. 
I love the twist which I DID see coming. Only thing that didn't work for me was the source of Maddie's funding. I know she applied for a credit card, but those have limits and so, unless mom was okay with it, her seemingly inexhaustible credit card limit was a bit far fetched, but hey... it's fiction.  :-) 
Since you might not have read the book yet, this isn't making any sense to you, but I have to write it like this because I don't want there to be any spoilers. Recommended MOSTLY for those looking for something to read after TFIOS.

I will always write back is the true story of Caitlin, a girl living in Pennsylvania, and the pen pal she writes to when she is in the seventh grade, Martin a studious boy living in abject poverty in Zimbabwe. Although most of her friends stop their correspondence, something clicks between Caitlin and Martin and they keep writing years beyond the initial pen pal project. She initially has no knowledge of his living conditions, and the story is told in an honest way that informs without making the reader feel sorry for Martin. It is a story that illustrates how important school is to many children, and what they will endure in order to be able to attend. I highly recommend this as a read aloud for reluctant readers in grade seven or eight who have lost their appreciation for education. It is extremely thought provoking and is sure to lead to many interesting discussions.