Set in the reign of Henry III, the Green Branch is a sequel to The Heaven Tree. The last book ended with gifted mason Harry Talvace being executed by Sir Ralf Isambard, while his family escaped over the border into Wales. Now Harry's son (also named Harry) has grown up under the protection of Prince Llewellyn and he has vowed vengeance. Harry attempts his revenge on Isambard, helped and hindered by Welsh border politics and the twisted character of Isambard himself.
The novel falls into roughly two halves, with the first detailing the situation in Wales and the second following Harry and Isambard's interactions.
Pargeter mixes some of her favorite historical personage (notably, the Welsh royal family) with the fictional Harry, who is hotheaded, naive, and likable. Ralf Isambard is a fascinating villain. His motives are remarkably unclear. He is always one step ahead of Harry, always knows what buttons to push, always the master of the situation.
Pargeter has a drier, less emotional, less soapy feel than many other authors who write in the same era (Penman, I'm looking at you), which may make her prose slow going for some. There is a refreshing lack of angst.
As is usual, Parteger's creates a wholly believable medieval world, whose inhabitants act thoroughly of their age and time, and yet whose motives and feelings are easily understood by a modern reader. I enjoyed it very much and am eager to read the follow-up.