That paranoia plays a large role in Castle’s plan for retribution, which is shaped by his knowledge of the Saint family’s personal dynamics as well as their illegal enterprises. Castle’s strategy is to undermine Howard Saint’s confidence in his greatest treasure – his family, which includes his best friend and lawyer Quentin Glass. “This is the sort of perverse aspect to Castle. He could simply execute Howard Saint on the golf course, for instance, but he chooses not to. It’s not enough,” says Hensleigh. “Castle can’t yet articulate it, but his philosophy has begun to take shape. As he says later, it’s not about revenge, which is an emotional response; it’s about punishment. If he could articulate it, I think he’d say that certain crimes rise to a level of unconscionability or egregiousness that they fall into the category of those that require proportionate punishment.”
Hensleigh enlarged the roles of Castle’s tenement neighbors, Joan, Dave and Mr. Bumpo, who appeared in the Welcome Back Frank series. The trio becomes Castle’s one connection to human community, humor and warmth, and they ultimately allow him to see beyond the scope of his pain. “They're all broken people. Castle is a broken man. He heals them; they heal him,” Hensleigh allows. “Through the softening and humanizing effects of this new surrogate family, and the fact that he had to come to their aid – because these are people that he cares about – he realizes that he has a broader role after the vengeance of his family is concluded.”