"You've got it. Hydrocephalus can be acquired or congenital, which is not to say hereditary. The term simply means the condition is present at birth."

"I found the shunt in a normal-looking skull. Doesn't hydrocephalus result in increased head size?"

"Only in infants, and only if left untreated. As you know, with older children and adults the bones of the skull are already formed."

"What causes it?"

"There are lots of reasons for inadequate CSF drainage. Prematurity puts an infant at high risk. And most babies with spina bifida have hydrocephalus."

"Spina bifida involves a neural tube defect?"

"Yes. The problem occurs during the first four weeks of gestation, often before the mother knows she's pregnant. The embryo's neural tube, which develops into the brain, spinal cord, and vertebral column, fails to form properly, leading to varying degrees of permanent damage."

"How common is it?"

"Entirely too common. It's estimated that spina biflda affects one in every thousand babies born in the United States, and about one in seven hundred and fifty born in Canada."

"I recovered no vertebrae, sol have no way to know if my young lady had spina bifida."

Russell nodded in agreement, then continued her explanation.

"There are many other causes of hydrocephalus besides spina bifida." She ticked them off on her fingers. "It can result from brain hemorrhage. The inflammation and debris resulting from brain infections, such as meningitis, can block drainage pathways. Tumors can cause compression and swelling of brain tissues and result in poor drainage. So can certain types of cysts. And hydrocephalus can be familial."

"It can be inherited?"

"Yes. Though that's rare."

"So where does the shunt come in?"

"There is no way to cure or prevent hydrocephalus. For the past forty years the most effective treatment has been the surgical insertion of a shunt. The one you've brought is a bit outdated, but it's really pretty typical.

"Most shunts are just flexible tubes placed into the ventricles to divert the flow of CSF. They consist of a system of tubes with a valve to control the rate of drainage and to prevent back flow. The early ones diverted the accumulated CSF into a vein in the neck, then into the right atrium of the heart. Those are called ventriculo-atrial, or VA shunts. Some VA shunts are still used, but there are problems associated with them, including infection, and, though rare, heart failure due to blockage of blood vessels within the lungs by particles of blood clot flaking off the shunt's catheter tip. Most shunts now drain into the peritoneal cavity They're called VP shunts."

She indicated the device I'd pulled from the skull.

"This is a VP shunt. In the living patient you would have been able to feel the bottom tube ninning under the skin that overlies the ribs. That part of the device is missing."

I waited for her to go on.

"The peritoneal cavity is large and can usually handle any amount of fluid delivered by the shunt. Another advantage of draining into the abdomen is that the rhythmic contractions of the intestinal organs move the tip of the catheter around. That motion prevents its becoming blocked or sequestered in scar tissue.

"When do these things go in?"

"As soon as hydrocephalus is diagnosed. As much as thirty-six inches of tubing can be placed in the abdomen of a neonate. As the child grows, the tubing unwinds to accommodate the increased length of the torso."

"I found a small hole in the skull, near the parieto-temporal junction."

"That's a burr hole. It's drilled during surgery to insert the upper end of the shunt into the brain. They're usually made behind the hairline, either at the top of the head, behind the ear, or in the back."

Russell's eyes flicked to a round metal clock on her desk, then back to mine. I was anxious to learn what difficulties might be caused by hydrocephaly, but knew the woman's time was limited. That research would be up to me.

I gathered my jacket and she returned the shunt to its jar, curling the paper and allowing the device to slide gently into place. We rose simultaneously and I thanked her for her help.

"Do you have any idea who your young lady is?" she asked.

"Not yet."

"Would you like me to send you some reading material on hydrocephalus? There are problems associated with the condition that you might find helpful."

"Yes, very much. Thank you."

I left the neuro and went directly to Carajou headquarters for the second of Roy's review sessions. The meeting was already in progress, so I slipped into a back seat, my brain still processing what I'd learned from Carolyn Russell. Our conversation had raised as many questions as it had answered.

How had the hydrocephaly affected my unknown girl? Had she been sickly? Disabled? Retarded? How did a teenager with that condition end up buried near a biker headquarters? Was she a willing participant, or another innocent, like Emily Anne Toussaint?

This time Roy was using transparencies, and a bulleted list filled the screen. I forced myself to focus.

"Outlaw motorcycle clubs are characterized by a number of common elements. Most OMC's are organized according to the Hells Angels model. We'll come back and look at that structure in some detail."

He indicated the second item.

"All clubs have membership which is very selective, and 'prospects' or 'strikers' are required to prove themselves to earn their colors."

He moved down the list.

"The colors, or club patch, are the member's most valued possession. Not everyone wears colors, however. Individuals who are useful to the gang are allowed to interact as associates without actually joining.

"The primary focus of an OMC is criminal activity. Each club has rules that condone violence to further the interests of the club and its members. Intelligence gathering is intensive, including the monitoring of other gangs and of law enforcement personnel."

Roy pointed his pen at the last item on the list.

"The clubhouse, which is often strongly fortified and elaborately outfitted, is the meeting place for club activities."

I thought of the Vipers' house in St-Basile, and wondered what activities could have included a sixteen-year-old girl with hydrocephaly.

Roy removed the transparency and replaced it with another, this one a tree titled "Political Structure of an OMC National."

Roy explained the hierarchy, starting at the bottom.

"The basic element of the OMC structure is the chapter An independent outlaw motorcycle club becomes part of a larger organization, such as the Hells Angels, only after a charter has been approved by vote of the national membership. This involves a long process that we can discuss later if we have time.

"Each chapter operates in a specific local area and maintains a certain degree of autonomy, but must live by the rules set out by the organization. These rules, either in the form of bylaws or a constitution, define the rights and obligations of the members and the gang.

Roy slid a new transparency onto the projector. This chart was labeled "Political Structure of an OMC Chapter."

"Each chapter has its own controlling body, or executive, elected by the members. Typically there's a president, vice president, secretary-treasurer, and sergeant at arms. These are the guys responsible for maintaining order within and peace outside the group.

"Guess none of our local morons will make the Nobel short list this year." Kuricek was up to form.

Roy waved down the laughter.

"There's also an elected road captain who takes charge of the runs. Then there are the rank-and-file members-"

"And he does mean rank." Kuricek held his nose.