At $8 Detective Comics #19 is overpriced for anyone who isn’t a huge fan of Man-Bat. All but one of the stories (involving Bane created a Venom-powered army to continue his vendetta against the Court of Owls) contained in this issue deal with Batman responding new a Man-Bat outbreak (which includes a Man-Bat version of Zsaz) started by Emperor Penguin to steal Gotham blind during the chaos or its consequences.
In an inexplicable chronological snafu set by the launch of the New 52 (and Grant Morrison‘s insistence to keep using Man-Bats as Talia‘s soldiers), we get out first introduction to Kurt Langstrom (the scientist who invented the Man-Bat serum) and, in the New 52 version is far, far, far from being the first to transform into a half-man/half-bat hybrid.
Other stories involve Emperor Penguin’s soldiers bilking Gotham out of millions, the Penguin planning his escape from prison and revenge against his former assistant, Mrs. Langstrom’s plans to save her husband, and a disagreement between cops, one of whom was infected by the Man-Bat virus, over Batman’s proper role in the city. For fans.