Batman: Cacophany written by Kevin Smith, penciled by Walt Flanagan, and inked by Sandra Hope
Deadshot is hired to invade Arkham Asylum and kill the Joker. As he's hauling the Joker out, another masked criminal shows up and "liberates" the Joker from Deadshot. The new criminal has a black mask with two concentric circles on the front. He never says anything except for repeating sound effects from previous panels so he has the name Onomatopoeia. He gives the Joker a lot of money and disappears into the woods. Batman gets to chase down the Joker yet again.
The Joker is on a bit of a rampage. Crime lord Maxie Zeus (who occasionally has delusions of Greek godhood) has altered Joker's poison gas into a popular street drug called "Chuckles." It's only occasionally fatal (usually overdoses), which is maddening for the Joker. As if he needs to be madder. But since the Joker has a clear agenda, Batman has a clear course of action to stop him. Unfortunately, Onomatopoeia is after Batman so plans are bound to go awry.
The plot is reasonably complex but a lot of the surprise twists are predictable. Smith brings out various aspects of Batman and Joker's relationship which have been covered in other places. Onomatopoeia is a very boring villain and comes off more like a plot mechanic than a person. It's implied he's killed a bunch of other superheroes (the most famous being Green Arrow), so maybe there are other stories that make him more interesting. He isn't interesting here. Kevin Smith also throws in a bunch of his style of sex jokes which really don't fit well with a Batman story; he should be writing Deadpool.
So I can't recommend this book unless your a Batman completist or a Kevin Smith completist. Smith says in the introduction that this isn't the best Batman story he could write and mentions The Widening Gyre as his soon-to-be-release Bat-mangum opus. I have no interest in trying it out.