Morgawr is the third book of The Voyage of the Jerle Shannara.
Morgawr is almost as dark and compelling as Antrax and it's written for adults. Morgawr contains the same science fiction elements, which were introduced in Antrax and they make this book interesting. I liked this book very much.
If you enjoyed reading the two previous books, you should read Morgawr. You should also check out The High Druid of Shannara series (Jarka Ruus, Tanequil and Straken), which Terry Brooks wrote after this series.