Hi all hoping someone may know of or have an idea of who wrote this book.
The plot is that a wizard/magician who is named Gil from another world somehow ends up in our world during World War 2 and is captured and held by the Nazi occult division and is made to teach them magic that they would try using in the effort with the war. He eventually realises that they are not the good guys and bends his efforts to gain supplies and information as to where magic lines of power are strong enough near his location to allow him to use them and transport himself home to his own world. In the end, he successfully gets home.
I can't remember the author's name. I thought it was titled Well of Echoes, but I'm but not sure. I read the book roughly 15 years ago now (2013-14).