Hellifax is the third book in the Mountain Man series but the events within it occur simultaneously with those of book 2, Safari, so in a way is more like book 2b than book 3. This time around we follow Scott and his desire for revenge against Tenner which takes him to the city of Halifax. Back in the first book, Mountain Man, Scott and his two companions ran into Tenner and that encounter ended with Scott being shot in the back and left for dead. Barely able to survive his wound, Scott awoke to a gruesome scene of torture and the bodies of his two friends who were skinned alive by Tenner. Scott then vowed to avenge his friends and this book finally provides the details of that attempt. Scott is a big man, but he is no killer, so despite his desire to make Tenner pay for his crimes there is no guarantee that Scott has what it takes to make that happen. Luckily for him he runs into Amy.

Book two of the Mountain Man series picks up right after book one as Gus recovers from the attack on his home that almost killed him. His poor state of health forces him to venture into the city to find pain killers to aid in his recovery so he makes sure to also grab supplies (mostly booze.) When he begins to feel better he decides to take advantage of the winter conditions and fight back against the zombie horde down in the city while the cold and snow hampers their movement. This leads to the advancement of one of the more intriguing threads from the first book - why do the zombie corpses completely disappear within a few days after they are killed for good? When Gus finally uncovers the root cause behind the disappearances, he finds himself facing a new threat even more menacing than the zombies themselves. 

Book one of this series, We Are Legion, was a unique take on the future of the human race. A future that became dependent on self replicating probes implanted with the personality of a cryogenically frozen, sarcastic, sci-fi geek named Bob. With Earth dying and becoming non-viable, Bob and all his replicants are busy doing what they can to find viable homes for the humans left on Earth; however, finding enough habitable planets and getting everyone off Earth in time is no easy task.  To that end the Bobs make great strides in technology that allow them to better fulfill their role as humanity's caretakers but the challenges they face are also increasing at an alarming rate. Those challenges include first contact with alien races, both more and less advanced than Bob, domestic terrorists that threaten the survivors on Earth, and Bob's personal struggle with the fact that he is no longer human.

After two generations the research colony on Venus has lost most of its funding so the discovery of a possible alien artifact on the planet's surface couldn't come at a better time. It means an influx of money, but also a team of experts and security agents from the United Nations which has ruthlessly controlled the colonies since Mars tried to declare independence. Elsewhere in the galaxy, an alien planet is slowly dying. Their scientists have finally identified a world they can terraform. However, there is another intelligent species in the same solar system who might have a prior claim. There are those on both sides willing to do anything for their survival even if it means xenocide.

Augustus "Gus" Berry lives alone in the mountains, that is unless you count Uncle Jack (Daniels) and Captain Morgan who he spends a lot of time with every day. He was a painter, not a soldier, before the world changed but now he wields his Boomstick and baseball bat with the skills of a pro. Gus takes no chances because he knows that it only takes one mistake for the zombies to get the better of you, but winter is coming and needs to venture down into the city to scavenge supplies. He works over the houses because the obvious locations like stores and malls were picked clean long ago, but going through houses can be a bit of a crap shoot. Most don't have much but every now and then you hit a good one. Gus suits up and makes sure that he is prepared for whatever the zombies may throw at him but he isn't quite ready for what other humans might have in store.

Everyone agrees that Lucinda should have been born a witch, with her personality and obsession with the Fire Guild. Or was she born a witch? Unaware that she's putting herself on the frontline of the coming war with the neighboring Empire she petitions the Fire Warlock for assistance in finding a husband. Living in his fortress with access to his library and studying with the handsome flame mage Sven is a dream come true except Lucinda keeps having nightmares. The King is convinced that the Fire Warlock, Quicksilver, is a power hungry wizard holding back the nobility out of spite and Lucinda has learned that the situation is hopelessly complicated. The Office of the Western Gate, that grants the Fire Warlock the ability to draw on the power of the volcano Storm King, is a magical construct known as a Lock. The Fire Warlock is charged with protecting the border and if the Warlock fails to act the Lock will simply incinerate him and pass the mandate to his successor. Above all, the Lock will maintain the sovereignty of Frankland, even if the inability to surrender in a war means their utter destruction. If only there was another warlock with the gift to craft Locks who could fix things because the seers agree that Quicksilver won't be the Warlock much longer.

For the first five books of the Frontlines series humanity was pushed from their many homes amongst the stars back towards Earth. The aliens known as Lankies eventually set up a foothold on Mars and began to batter Earth and put humanity on the brink; however, in the last book we saw the human forces finally push back. Although the Lankies are still on Mars it is no longer a launching point for their military and human forces control the orbital. This book starts a number of years later over the last few years there has not been a single Lankey attack launched against Earth so of course it is time to get curious and figure out what is going on. What better way to do that than to head back out of our solar system and see what the Lankies are up to elsewhere. What could possibly go wrong?

Isao Ryotora is dispatched to the remote mining village of Seibo Mura following a bizarre attack by various creatures from the spirit realm known as yokai. As a shugenji, one who can communicate with the kami, Ryotora is not a warrior and he has little experience dealing with yokai. Not that anyone has really dealt with a situation like this before where so many unrelated yokai went from simple harassment to murderous destruction over the three nights of the full moon. The entire situation is made even more uncomfortable due to the presence of a scholarly samurai of an influential family, Asako Sekkin. His elegant manners only remind Ryotora that he was born a peasant in this very village before being adopted into a samurai family, but Sekkin is determined to help Ryotora with his investigation. This is because he has been plagued by a dog spirit that has allowed him no rest until he arrived in Seibo Mura. A great evil is rising but with Sekkin's knowledge of yokai folklore and Ryotora's skills as a shugenji they might be able to unravel the secret history of this place and save the empire.

The Stone Eaters aren't exactly human but the fate of humanity is in their hands. Now that Alabaster has set into motion a plan to return the Earth to its former state, where Fifth Seasons don't happen at all, it has forced the Stone Eaters to take sides. One side is supporting Essun and her quest to finish what Alabaster started, which means returning the Moon to its former orbit around the planet. The other faction is seeking to prevent Essun from doing so and hoping to instead crash the Moon into the Earth so they can finally achieve peace by ending their dreary immortal lives.  Of course they will need the help of an Oregene even more powerful than Essun to pull this off and they just happen to have one. Things are going to get awfully messy when Essun finds out that the Orogene supporting those Stone Eaters, and standing in the way of her attempt to save the planet, is her own daughter.

The planet would survive but humankind was probably doomed. There was indeed a solution but it couldn't be finished in time to save civilization. So they built what they could and left artificial intelligence to finish the job in the hope that any survivors would need it in the future. Assuming that their descendants would have the scientific knowledge to make use of their creation there was still the problem of how language would change over 12,000 years. They built Atlantis, left a code, and hoped for the best. Now a small group of scientists has less than a week to crack it. They will need to venture under the ice of Antarctica in the middle of a war, escape nanoswarm lifeforms that would prefer humans die out, and crack the code that might explain how to use a machine beyond their science.