This Is How You Lose the Time War

The authors threw me into the ‘deep end of the pool' and I sank.

Where's the bit of backstory to get you settled in? And more importantly with all the jumping about, I can only assume because there's no history of the timeline, I'm completely lost and frustrated.

Where are the definitions of some of the terms and groups involved?

I need this in the beginning pages, or sprinkled among them at least, or I drop the book.