The Scorched Earth trilogy is a group of three B.P.R.D. miniseries that together form a larger arc.
The three are:
Additionally, the story Out of Reach was published as an introduction to The Warning, making it a prelude to the trilogy. The Scorched Earth trilogy serves as the conclusion to the Plague of Frogs cycle and is collected in its entirety in the fourth B.P.R.D.: Plague of Frogs omnibus edition.