Reddit mentions of The Lost Books of Merlyn: Druid Magic from the Age of Arthur

Eh magick no. 'Occult' yes. The 21 Lessons of Merlyn: A Study in Druid Magic & Lore and its sequel The Lost Books of Merlyn: Druid Magic from the Age of Arthur use story, between lesson sections, to teach Monroe's peculiar flavour of Druidic and Celtic Reconstructionism. A lot of folks find both text to be complete garbage though but I think that is a bit unfair, he wrote two books outlining his belief system and practices and I think everyone is entitled to dance to the beat of their own drum and believe what they want.

Edit: another that comes to mind is The Miracle of New Avatar Power although again not quite. It uses something similar to magick with stories sprinkled between content... if someone wanted to eventually dip their toe into goetia I'd start with this (you can readily find pdf copies around the internet) as it is something that is very simple to do and one can build discipline with it then move into something like goetia that requires considerably more preperation and steps for proper ritual. It is out of print and should you ever see this book at a garage sale or used bookstore BUY IT because they resell quite well for a nice markup.