Detective Comics: The Joker War picks up where the previous volume left off and collecting the next seventh issues (Detective Comics #1020–1026) of the 2016 on-going series, a story from Detective Comics #1027, Batman: Pennyworth R.I.P., and Detective Comics Annual #3 and covers seven stories.
"Ugly Heart" is a three-issue storyline (Detective Comics #1020–1022) that has Bruce Wayne as Batman confronting Harvey Dent as Two-Face. Two-Face has turned cult leader now, and it seems tied to the end of Big Burn where he'd shot himself in the head. Apparently, The Joker fitted him with a controlling device (via Hugo Strange and Mad Hatter), and has been forcing Harvey to build up his cult. It is an interesting story as the Harvey persona teamed with Batman against Two-Face.
"Prelude to Joker War" is a two-issue storyline (Detective Comics #1023–1024), "Tales from the Joker War" and "Monster Men" are a one-issue storyline (Detective Comics #1025 and 1026 respectively) that collects the many tie-in stories of the Joker War with villains in Hugo Strange, Lincoln March and the Talons, Mad Hatter, Two-Face, Killer Croc, and of course the Joker and it is up to Batman and his compatriots to take them on.
"Blowback" is a short story from Detective Comics #1027, which has Bruce Wayne in a death trap, which would be release only if he dies. As Batman lays submerged, he ponders his past and figured a way out. "Who Dares Wins" is a one-issue storyline (Detective Comics Annual #3), who has Bruce Wayne as Batman going after an unmemorable villain, but shows his life after Alfred Pennyworth's death. Finally, "Batman: Pennyworth R.I.P." is a one-issue special that has Bruce Wayne, an amnesiac Dick Grayson, Barbara Gordon, Jason Todd, Tim Drake, and Damian Wayne to come together and remember their faithful and fallen ally.
Peter Tomasi penned the entire trade paperback with some help from Brad Walker (Detective Comics #1024) and James Tynion IV (Batman: Pennyworth R.I.P.). For the most part it was written moderately well. In truth, individual the stories works well on their own, however combined in one trade paperback it give an overall mediocre feeling as it lacked focus and felt the storyline and the reader into too many directions. Furthermore, it doesn't help that tie-in are notoriously bad when separated in trade paperback form.
Brad Walker (Detective Comics #1020–1023), Kenneth Rocafort (Detective Comics #1025–1026), Sumit Kumar (Detective Comics Annual #3 and Batman: Pennyworth R.I.P.), Norm Rapmund (Detective Comics #1024), Brad Walker (Detective Comics #1027), Eddy Barrows, Diogenes Neves, Marcio Takara, Chris Burnham, Eber Ferreira, and David Lafuente (Batman: Pennyworth R.I.P.) penciled the trade paperback. For the most part the pencilers have distinct penciling styles and suffer from too many cooks in the kitchen, as some pencillers are better than others, and it is up to the individual taste, the artistic flow suffers greatly.
All in all, Detective Comics: The Joker War is a mediocre continuation to what would hopefully be a wonderful series.