The Fallen Queen (Titans Book 3)

The concluding book of the Titans series ramps up the stakes. The bad guys are set to not only take over earth but all planets in the universe. Their "home" planet is actually a planet that was occupied by another group before. There are various skirmishes and a unified plan by Titans, Greeks and others. However, odds were not looking good. Then the book suddenly came to a conclusion. The queen was killed, then all of the others started to fight for dominance. The "friendly" daughter ended up becoming queen and suddenly all the mimics stopped and world peace was in place. 

The Missing (Titans Book 2)

The middle Titans book continues with escalating stakes. The mimics have infiltrated earth and are set on planetary domination. There are many cases of travel through the solar stream. It is hard to tell who is a good guy and a bad guy. The remaining real titans teamup with the snakes to try to defeat these mimics. Flying horses gett sot from the sky. This book is really not a standalone book and builds off the first and leaves many holes unresolved for the next.

The End of Olympus (Pegasus Book 6)

the final Pegasus book takes things to greater extremes. It is now the universe that may be in danger. There are mutant titans that suck power. The only way they are defeated in the end is by having them suck too much power. In between, the goodguys go Wandering Earth and move a planet.

The book is a showcase for modern individualistic values. Don't let a single person get harmed,e harmed, even if that means saving millions. After all, there will end up being some way to magically save those millions after all. In the end Emily becomes deified and somehow makes some big sacrifice that doesn't seem to be a sacrifice at all. 

Titans

Titans is a sequel to the Pegasus series. The Titans and Olympians are at peace. the kids are all going to school. The book is much more lighthearted than the Pegasus books. It also as written intentionally as a multipart series. This book ends on a cliffhanger with nothing wrapped up. 

Random beings, including humans start showing up on the Titan planet. The adults try to lock them up, but the kids realize something is going on. It turns out there are some shapeshifting monsters on the planet that are masquerading as beings that they captured. A ragtag group of kids sneaks into preison to find real Titans and Olympians and escape to earth to prepare for a battle royale.

Rise of the Titans (Pegasus Book 5)

New deities come on to the scene in the 5th Pegasus book. Even after Emily promises to take her battle elsewhere, we still get a battle between Olympians and Titans right over Hawaii. (They manage to show up just at the "wrong" time.) This books gets a little more confusing and contrived. Pegasus is flying around the world to eventually get to Hawaii. There the fallen shard is protected by a Hawaiian god. However, there is another girl that shares the power with Emily and her "head-mate".  This girl is a spoiled brat that wants everything. They eventually are able to defeat her and then join with her. The "super beings" also show up and banish the Olympians and Titans for misbehaving. Things get confusing, with some leaps in logic. But there are also some fun random moments with various gods exercising their personalities.

Origins of Olympus (Pegasus Book 4)

After going through many extreme stakes involving the destruction of worlds what's next? Time travel! On an architectural dig, a stone is found that causes Olympians to get sick and age. They need to go back in time to find it and restore peace. There is an CRU member that goes with them (and renounces the CRU.) Traveling on the solar stream also occurs. They need to prevent the Titans from destroying the Greek gods. They also need to make sure the gods are not youth, but. the proper age that they are remembered in history.  Everything works out, but it is somewhat sad that the shared experiences are now missing from others. 

The New Olympians (Pegasus Book 3)

New conflict arises in the third Pegasus book. The CRU has cloned a bunch of the Olympians. When they see their clones, they just want to destroy them. The Olympians decide they want to destroy the earth.  Emily is able to (too easily) talk them out of it. The most interesting part is the battle royale that takes place in Vegas, destroying a big chunk of downtown. Oops!

Olympus at War (Pegasus Book 2)

In the second Pegasus book, it is discovered that the bad guys from the previous book (Nirads) are not actually that bad. They are "goons for hire" who the Gogons are using to help conquer Olympus. And just to keep it fun, the other government agency bad guys are still in the way. Cupid is able to use his charm to help "defeat" the humans. However, the Gorgon's are a greater challenge that requires some alliances.

The Flame of Olympus (Pegasus Book 1)

A daughter of a police officer and a boy from foster care find a flying horse. There is also a teenager that managed to survive after seemingly being pushed off a tall building. An "evil" Central Research Unit is trying to interrogate all of these people to try to find out more. After testing, they think the teen must be an alien. However, the kids have found out the truth. They are all Greek deities from Olympus. There has been a big battle and things are dire. However, if they find the special girl that Vestus has invested with the fire of Olympus they should be able to defeat the demons that have invaded. The girl ends up discovering that she is the special girl. She willingly sacrifices herself, but then discovers that rather than being killed, she has been made whole. All seems to be doing well. The book contains various life or death scenarios with people killed - yet the stakes never feel very high. It is also fairly easy to guess what will happen, but this probably works well for the target audience.