Jack London died before he finished writing The Assasination Bureau. He had scribbled notes that were interesting and horrifying (but good) about how he'd like it to end... like birds breaking their wings against boats, dead sharks beating hearts in the hands of fishermen, and an Irish Terrier that jumps off into shark infested seas, all the while the protagonist lays dying.....
All these images seem fitting for a London ending, especially an end about a story of a group of assassins that think they are still morally straight, even as they attempt to take the life of one of their friends. It doesn't end like that though. Instead, a man by the name of Fish ends the story completely different. Not to give Robert L. Fish a hard time but the ending was not befitting of a London novel. Matter of fact, my guess is that it is the very ending London tried to avoid--the easy one.
I remember reading the ending to The Call of The Wild and my mind was completely blown by the raw intensity of the last paragraph written. The ending of Call of the Wild is the reason it remains one of the only books I've read more than once.
The Assassination Bureau is about sheer madness, yet it ends in the most mundane predictable way possible. I found it extremely disappointing. I can't help but feel that London would have been unhappy about it too.