To the Trinity and beyond!
I'm still plowing through articles and sources for a paper on St. Augustine's De Trinitate, but I think I've got the basic outline in my head. I had originally glommed on to his analogies (which occupy much of the book's second half), but things get technical very quickly in the secondary sources. So I've broadened my scope and will (briefly) survey the before-and-after of Trinitarian thought, including the so-called East/West split.