Everything seems to going well for Josef K. He's an up-and-coming executive at his bank, and seems to enjoy all the trappings of a swingin' bachelor lifestyle. Everything changes with his sudden and inexplicable arrest.
Even though K.'s under arrest, he isn't incarcerated, and his movements aren't restricted in any way. He can go to work as usual and enjoy all of his usual pursuits. His trial seems to be a vague and unreal affair – nothing to take seriously.
Almost imperceptibly, the trial invades K.'s life, saturating his every waking thought. He's perennially anxious and worried about how much other people know about his trial. He's frustrated with the lack of progress in his case, and he only gets more frustrated when he hires Huld to defend him. Huld's procrastination tactics convinces K. that he has to intervene personally in his own case, no matter how time-consuming his involvement has to be.
The prison chaplain's parable about one man's failed attempt to access the Law confirms K.'s worst fears about the trial. The parable attests to the indifference of the Law to the puny individual; K. can't possibly hope to make a dent in his case.
Like his arrest, K.'s execution is sudden, but fits in with the trial as a process that has gradually destroyed every aspect of K.'s life.