This is a reworking of Dickens' 'Christmas Carol' for the Dark Knight Batman mythos. 
 Apart from a clumsy confusion at the beginning as to who precisely is Bob Cratchit's 'boss' (either an egregious failure of continuity or a too-clever-by-half attempt to give the now somewhat cliched message of the Joker and Batman as two sides of the same coin), this works well. 
 But the book is not best read for the script which is fairly predictable (though well drafted and, as we will see, with a message) and really an opportunity to give star appearances to Cat Woman, SuperMan and The Joker for the fans but the art work which is dark, Gothic, precise and magnificent. 
 It opens with an atmospheric evocation of Gotham City in which you can see and hear (a remarkable achievement, here) the crunch of Batman's boots as he walks across a snowy roof. There is also a useful contemporary reworking of Dickens' moral which give nothing away to state here. 
 Whereas Dickens was castigating lack of generosity and miserly disregard for others, Bermejo is castigating the blind hunt for justice that stereotypes those on the margin as a-social regardless of their circumstances and which uses people as mere tools to some greater 'good'. 
 Batman is presented as on the very edge of psychopathy and drifting into the territory of Judge Dredd in a world where police and petty criminals are simply trying to make the best of a bad system. Wayne Enterprises is not pictured precisely in its standard context of beneficence. 
 This comic book is slight but it expresses a turn of sorts in the mind-set of a nation, away from simplistic notions of good and evil and (if tentatively) towards criticism of a world that has a place for vigilante superheroes with a cold attitude to the weak and vulnerable. 
 The vigilante trope was a creation of the Wild West and was urbanised first briefly by Dashiell Hammett (from a Leftish perspective) in the 1920s and then in Hollywood cinema during the 1970s with violent protagonists like those in 'Death Wish' or the Dirty Harry films. 
 The justice trope is standard American 'beacon on a hill stuff' and Batman was originally a fairly innocent figure until the tormented 'Dark Knight' figure appeared, while Judge Dredd always was a satire on America (a fact Sylvester Stallone may have missed). 
 To see both tropes now critiqued through a Victorian reformer's message by a relatively young graphic artist and writer is yet another sign that the younger generation of Americans are questioning cultural assumptions, even if at one remove.