This is my third post-apocalyptic series from Nicholas Sansbury Smith and unlike Hell Divers or the Extinction Cycle this one offers up a much more realistic, and therefore possible, scenario as a backdrop. Similar to One Second After this book shows us the impact of an EMP attack on a small community, which happens to be one of the author's favorite places to visit, Estes Park, Colorado. Trackers also broadens the canvas beyond the small community by detailing the impact the attack has on the US government back in DC by following one of the Senators with some ties back to the Estes Park area.  To set it apart from the competition Smith also adds in a murder mystery and a good dose of American Indian folklore which gives it a unique flavor within a crowded genre.

Wolves picks up shortly after the end of Deliverance with X and Magnolia aboard the Sea Wolf  looking for the Metal Islands as a potential home on the surface that would allow humanity to leave the air and return to the Earth. Of course finding that new home is really just an excuse that X used to justify this mission and his real agenda is to kill the leader of the cannibalistic Cazadores who live in the Metal Islands. X quickly finds out that the sea is just as dangerous as the land and the mission goes south quickly as all manner of unexpected obstacles need to be overcome. The action sequences come one after another and let up just long enough for the story arc to move forward as the true cause of the war that devastated the planet is finally discovered.

The Extinction Cycle series picks back up as the fight against the Juveniles heads over to Europe. Kryptonite did its job against the Variants but the Juveniles are growing up now and they are much worse. Luckily in the U.S. most of the major cities have been reclaimed and there are now Safe Zones being established where refugees are gathering to start to rebuilding process; however, Europe is a different story. Over there the Juvenile threat was not dealt with when they were still young and now they have grown into something far worse than their US counterparts. That's bad news for everyone.

At the end of the last book, Plum Island was attacked and the Variants captured Dr. Lovato thus putting humanity's last hope in jeopardy. Kate was working on a new Variant killing weapon, Kryptonite, and Plum Island was the key to that weapon being ready on time. Of course Master Sergeant Reed Beckham is not going to stand around while the woman he loves is taken to her death by a bunch of mutants so this book starts off right in the action with a rescue mission that is a race against time.

The number of humans left alive continues to drop at an alarming rate and there isn't much time left. It has only been a few weeks since the apocalypse began and so far all efforts to slow it down have failed. The Variants control all of the major cities and Central Command is being moved to the last remaining Naval strike group as no place on the mainland remains safe. Does that even matter now that it is obvious that the military leadership can't be trusted? Team Ghost knows that they will pay for their actions at the end of the last book and all they can do at this point is to protect Dr Lovato at all costs. She is the only hope there is of coming up with a solution before it is too late and nothing can be allowed to happen to her. At least things can't actually get any worse at this point can they? Actually, yes they can...

Mankind has experienced many ages over the years, but few could have predicted the age that would come next. As the Industrial Age gave way to the Information Age the possibilities for advancement were endless but out of nowhere the Extinction Age was upon us. With the human population falling at an alarming rate humanity has only a handful of weeks remaining before going extinct unless something is done to change the trajectory. With Operation Liberty a failure it is now obvious that the military is not the answer so all eyes return to Dr. Kate Lovato in the hope that science can offer up an answer before it is too late. To make matters worse, resupply from central command is not possible so there may not even be enough food to sustain Kate and her team for the little time that remains.

By the end of book one it was revealed that Dr. Kate Lovato's bio weapon, which she designed to destroy the zombie hordes, was quite effective, but also not effective enough. Doing the math we know that 80% of the human race had turned into flesh craving zombies before her weapon was deployed, and that her weapon killed billions of them, but it also left behind a resistant strain of Variants. The real question is, how many Variants are there and what are they capable of? Do they number in the thousands or the millions? Can this new threat of intelligent, agile Variants be contained or is it actually a bigger problem than the billions of mindless zombies that were wiped out?

Ebola is one of the scariest threats to humanity that nature has to offer and we live in fear of nature morphing the disease into something that can't be contained. Of course this means that a military project to weaponize the disease can't possibly have a good outcome so when a facility working on such a project goes dark, Delta Force Team Ghost is called upon to investigate what happened. Master Sergeant Reed Beckham has led his team into danger many times but this time he is not prepared for what they find. With the military leadership telling only half truths to keep their involvement in the project a secret, team Ghost finds itself involved in a series of events that could very will mean extinction for the human race.

Commander Michael Everhart, aka Tin, isn't the first Hell Diver to be betrayed by the leadership aboard The Hive but he is determined to be the first to actually do something about it. His dive team has acquired an airship of their own, Deliverance, and they have also found strong evidence that X actually survived his fall back to Earth 10 years ago. Not only survived the fall, but apparently actually found a way to survive on the toxic surface for an extended period of time. Even if X is no longer alive the truth of what happened to him must be uncovered, so searching for that truth becomes the top priority for Tin and his team. Payback for Captain Jordan's betrayal will need to wait for the moment; however, his time will come...

Ten years have gone by and much has changed for the remnants of humanity that remain aboard The Hive. Leon Jordan is now the Captain and Tin has grown up to become the Commander of team Raptor. It is no surprise that he decided to follow in the footsteps of his father and X and become a Hell Diver since X's loss is still felt to this day. X may be gone, but he is not forgotten, and his final sacrifice has turned him into a role model that still gives people hope, which is in short supply. Captain Jordan has abandoned Captain Ash's belief that humanity would one day return to Earth and he is willing to do whatever it takes to convince the rest of the crew that the surface is forever lost. However, walking away from the dreams of so many people is bound to have consequences...