Continuity mistake: In the previous book, Dark Assassin, Monk goes through Durban's notes and finds the only case of his which "remained a mystery" (Ch. 7). The case Monk reopens in the next book, Execution Dock, is also repeatedly referred to as "the one case Durban had not solved" (e.g., Ch. 1 and Ch. 5). The mistake is that there is no way these are the same case. The one from Dark Assassin involves the murder of a 40-year-old barber named Roger Thorwood; the one from Execution Dock is the sexual abuse and murder of a boy named Walter Figgis, by a man named Jericho Phillips. None of the suspects, victims, or witnesses in the two cases overlap at all. Of course Durban could have worked on both cases but they can't both be the one single case he never solved. And if they are both unfinished, then it is wrong to say (as the author does repeatedly in Execution Dock) that there is only one case Durban didn't close. (It also can't be a character mistake on Monk's part, since he knows about both cases).