Viking: The Plains of Althing

I enjoyed reading this historical novel of tenth century Iceland. It is the first book in a norse adventure trilogy.  However, there were a few problems that affected my enjoyment of the book. The blurb:

"A corrupt chieftain plots to rule all of Iceland and his steward Kel Coessen may be the only man who can stop him. But there's a catch: if Kel dares to defy his leader, Kel's love Aldis will be killed. A fearless slave called "The Black Mountain" starts Kel down the treacherous path of treason-and when the chieftain commits a loathsome crime, Kel snaps.  An unforeseen force draws Aldis to a place she vowed never to return, forcing her to confront her past-and a long buried secret threatens her future.  As strife grows, others meddle: a bishop eager to convert pagans, and a foreign jarl's furtive agent with her own designs on the country's young democracy."

The first third of the book was enchanting. I loved the characters and looked forward to reading more about them. However, the middle of the book was about additional characters instead and I quickly lost interest. I finished the book to find out what happened with Kel, Aldis and Tor, the "black mountain" slave. I am curious about their future stories, which makes me want to read book 2. Tor's story in particular is compelling but I am not yet sure whether I will take the plunge.