All Star Western #4

"The trail of a missing child from a wealthy family leads Jonah Hex and Amadeus Arkham into the watery catacombs of Gotham City's still-under-construction sewer system - but will they survive the many dangers that lurk in those twisty depths? Also: introducing the Barbary Ghost, a fireworks wielding mistress of vengeance, stalking San Francisco's criminal underworld."