Netflix is riding high on the success of fantasy series The Witcher, but with The Letter for the King, the streamer aims to deliver a more age-appropriate fantasy story adaptation. This source story hails from Tonke Dragt, the Dutch writer/illustrator of children's books whose "De brief voor de Koning" was first published in 1962 to much acclaim and success. A sequel story, "Geheimen van het Wilde Woud" (The Secrets of the Wild Wood) was published in 1965, so if this live-action series generates momentum, perhaps we'll see that story come to life as well. From …