The books 'Kate Greene of Earth' (myBook.to/KateGreene) and 'Stacey Kaunis of the Milky Way' (myBook.to/StaceyKaunis) are free to download until April 26th.
The 'Daniel and Kate' series is one of the very few story-lines that I have which is written out specifically as a discrete trilogy in sequential order. Most of my other 'trilogies' have one or two books that may follow one after another followed by either a prequel or a character story. Such as Soul-Eater-->Gospel of Lizzie (direct sequel) and 'Gospel of Tempter' (character story set in same universe).
In truth, 'Daniel and Kate' started off as a very-long, single book. As I began to clock over 100k words, and still only half-way into the story, I decided to split it up into a trilogy. For this reason, the books flow one right into another quite seamlessly as they were all at one point a singular story.
As a side-note, 'Kate Greene of Earth' happens to be one of my 'cleanest' books. It's focus on political satire, rather than tense action or emotional turmoil, leave it with absolutely no sex scenes, minimal violence and limited cussing. It's almost clean enough to qualify as a YA book... almost. It was fun to write and is a bit more whimsical, with features such as the first real alien on Earth being pressed into playing the role of an 'alien' in B-movies. Of course, the whimsy ends when the Dartuians return in an effort to bribe mankind to help them in their civil war.
Suddenly, Stacey Kaunis, the least likely hero, has to save the world and meets the man.... er.... poisonous but lovable alien frog of her dreams along the way.