This is a well-loved series. Vic is such a deeply flawed individual that you can't help but love him and feel for his struggles, even though sometimes you want to shake him. Jacob is really the perfect partner, though sometimes he is equally frustrating. 
 This story in particular, with the incubus, highlights the level of intense interest Jacob has for Vic, and equally the way Vic just doesn't see it. 
 This story is a wonderful introduction to a great series.