After our call, I hurried to the imaging section, scanned Kessler’s photo, and transferred the. jpg file to the computer in my lab. Then I hurried back, logged on, and transmitted the image to Jake’s in-box at UNCC.

Back to Ferris’s shattered head.

Cranial fractures show tremendous variability in patterning. The successful interpretation of any given pattern rests on an understanding of the biomechanical properties of bone, combined with a knowledge of the intrinsic and extrinsic factors involved in fracture production.

Simple, right? Like quantum physics.

Though bone seems rigid, it actually has a certain amount of elasticity. When subjected to stress, a bone yields and changes shape. When its limits of elastic deformation are exceeded, the bone fails, or fractures.

That’s the biomechanical bit.

In the head, fractures travel the paths of least resistance. These paths are determined by things such as vault curvature, bony buttressing, and sutures, the squiggly junctures between individual bones.

Those are the intrinsic factors.

Extrinsic factors include the size, speed, and angle of the impacting object.

Think of it this way. The skull is a sphere with bumps and curves and gaps. There are predictable ways in which that sphere fails when walloped by an impacting object. Both a. 22-caliber bullet and a two-inch pipe are impacting objects. The bullet’s just moving a whole lot faster and striking a smaller area.

You get the idea.

Despite the massive damage, I knew I was seeing an atypical pattern in Ferris’s head. The more I looked, the more uneasy I grew.

I was placing an occipital fragment under the microscope when the phone rang. It was Jake Drum. This time there was no leisurely “hey.”

“Where did you say you got this photo?”

“I didn’t. It-”

“Who gave it to you?”

“A man named Kessler. But-”

“Do you still have it?”

“Yes.”