The Dragons in Our Midst Series: Circles of Seven

The third installment of the Dragons in Our Midst series is here! Our two lovable halfbreeds are at it again, this time going into the bowels of the earth in an attempt to free lost prisoners and fulfill a prophecy, and in doing so, fire, brimstone, and goodness-knows-what-else breaks loose. Unlike many other series of books, which decline after the first one (or am I thinking of movies?) Circles of Seven adds more to the action, although the list of prophecies keeps going on and on and on.... Can we stick with one and fulfill it gradually over a course of four books?