Definitely a book that takes its time, both in getting to the point of itself and in its narrative plot, though not in the length it will take to read a chapter. I'm not sure if the decision to have many chapters and large header spaces was done deliberately or not, but it's definitely irritating and makes the first third of the book, in particular, feel so much more tedious. I normally enjoy reaching the close of a chapter, but when the event is occurring every two or three pages it just serves to cause narrative jolting. In hindsight, the odd structure may be deliberate so that the pace of the book actively increases as the character's journey itself nears completion, but a device that only makes sense as a whole isn't particularly useful for media consumed in parts.
It's not the only odd decision in the book. There's also the two intermission chapters, the last of which comes but pages from the end of the book. Both take place in a specific town, largely inconsequential to the story but in reality serving as a turning point in our character's lives. It is the only location we see twice, both on their outward- and return-legs of the journey, and in both instances see their path's crossed by a demonic child who enjoys poisoning people. Exactly what the purpose she serves was beyond me, other than to leave a somewhat unsettling feeling in my mind. Indeed, both the demon child and odd chapter spacing feel like the author read his finished work and realised it didn't evoke the correct emotions, so put in some odd narrative devices to force them on the reader. Whatever the reason, the book, for me, would have been much better without them.
The storyline itself is slightly more formulaic, though has odd moments both near the start and end which make it feel more fantastical then otherwise would be the case. Set in the West of the young USA during the Gold Rush period, we follow Charlie and Eli Sister, two brothers employed as hired guns and assassins. They have been dispatched to track down their latest target, a purported thief, and for the most part the book details their journey to find their mark. Once found, they discover that they have been lied to; far from being a thief himself, their employer is the one hoping to steal something, in this case a scientific formula for locating gold. It's this latter element, combined with aforementioned demon children, a strange old witch who possible lays a charm/curse on the brothers and the resulting conclusion that take an otherwise typical, well written Western and make it something slightly weird. I'm not convinced it works, but the gold formula does give the titular brothers fair reason to forsake their employer, allowing us to get to know Warm, it's creator, and Morris, another turncoat.
For it is with the characters it breathes life into that The Sisters Brothers shines. The plot is largely non-existent and the reasoning almost inconsequential, but it builds character narrative nicely. The slow pace and ramp of the first two-thirds helps introduce both Eli and Charlie without need for any active description, or even much backstory, yet by the close of the third act you both care about and understand them. Personally, though, I found myself most intrigued by Warm, the only character whose full life is discussed and who offers a sense of mystery to proceedings. That, though, is likely his entire purpose; a deliberate foil to the banality of Charlie and Eli, allowing their humanity to shine through in contrast to his over-the-top traits.
There is more than a little of the Of Mice and Men about the tale, leading me at times to wonder whether Eli, despite being the nominal narrator, was actually going to last the span of the story. In the end, though, it pulls a 180 switch and has Charlie come to ruin, though not as completely as in the Steinbeck classic. It was a nice and fitting touch, leaving the book, on the whole, on a firm ending note.
As someone who isn't drawn to the Western genre I can't speak on how well it fits within that scope, but it didn't make me yearn for more of the same. I'm also baffled at the number of quotes on the book jacket extolling the novel's humour, which I found utterly lacking. There are the occasional moments of witty banter exchanged between characters, but for the most part the plot is morose and sad, with no clear element of parody or comedy. That may just be my lack of knowledge on the subject matter, but I definitely wouldn't recommend The Sisters Brothers if you're after a light-hearted read or pick-me-up. In fact, whilst I enjoyed my time with Eli and Charlie, I don't think I'd recommend the book in general. It isn't bad, in fact in most ways The Sisters Brothers is a good book, but there also isn't any particular reason for you to spend time reading it over anything else.