I'm participating in Smashwords' July sale. A ton of books are on sale or free at Smashwords for the month, including all three of the full season bundles.
So Season One: Infected is completely free.
Season Two: Pursued is down to half price.
And Season Three: Unwoven is also at half price. That means you can get the entire series for less than $5. If you haven't gotten around to reading the books, then this is a great time to do so. Or a great time to buy copies of the series to give to friends.