The human body is very durable and resilient but at the same time very fragile and vulnerable.

Casey knew well over a hundred ways to kill a person, including the good old reliable double pop to the head. The appropriate method for any given mission depended on the circumstances one found oneself in.

Did they need to die slowly, with or without pain, aware of their surroundings or completely oblivious to what was happening? There was a whole smörgåsbord of menu items to choose from, including poison, nerve blocks, occlusion of the lymphatic system or blood circulation, even the digestive system.

Were you wanting messy or neat, recognizable body parts left over or just a greasy smear on the pavement? Something that could be played over and over again on CNN or a result so horrific that even the press wouldn't go near it?

There were considerations for volume as well. One corpse or three hundred? Three hundred in a group or one at a time in quick succession? Would they need to disappear off the face of the earth as though they had never existed or could they just be left where they fell?

Did you have to get up close and see their faces or could it be done from an F-14, quick zoom overhead, target, press the red button and back to the base for nachos and a beer? Or maybe eight months' careful infiltration of home and hearth, sometimes bed, then the surprised look of two seconds' realization before the wall behind their head is redecorated in red?

They called it wetwork but it wasn't always wet. A person can go forty days without food but only four without water. And maybe you could get some good intel as they beg for one sip from the bottle you place on the table in front of them.

Casey had pretty much done it all, in wartime and peacetime, all over the world. But none of his training and grisly experience had prepared him for the situation he found himself in now, dealing with Chuck Bartowski and his circle of family and friends.

Walker was getting sucked in and Casey was afraid he might be too. And yet, strangely, not afraid. Because it felt so good.

It was a new kind of death that Casey had only heard about before. He had always thought it was just a metaphor. But it was killing him. It was killing all his training, wiping out his emotional control, negating years of practical experience in the field. It was killing the cold-blooded killer in him. Casey didn't know how much longer he could hold out against it.

You see, Chuck Bartowski was killing him with kindness.