Outside the airport I suddenly felt sorry for myself as I struggled alone with briefcase and bag. I was tired and my clothes felt dirty. I was hopelessly overwhelmed and ashamed to admit it. I couldn’t even seem to get a taxi.

Eventually, I arrived at Quantico in a dented cab painted robin’s-egg blue with glass tinted purple. My window in back would not roll down, and it was impossible for my Vietnamese driver to communicate who I was to the guard at the FBI Academy entrance.

‘Lady doctor,’ the driver said again, and I could tell he was unnerved by the security, the tire shredders, the many antennae on tops of buildings. ‘She okay.’

‘No,’ I said to the back of his head. ‘My name is Kay. Kay Scarpetta.’

I tried to get out, but doors were locked, the buttons removed. The guard reached for his radio.

‘Please let me out,’ I said to the driver, who was staring at the nine-millimeter pistol on the guard’s belt. ‘I need for you to let me out.’

He turned around, frightened. ‘Out here?’

‘No,’ I said as the guard emerged from the booth.

The driver’s eyes widened.

‘I mean, I do want out here, but just for a minute. So I can explain to the guard.’ I pointed and spoke very slowly. ‘He doesn’t know who I am because I can’t open the window and he can’t see through the glass.’

The driver nodded some more.

‘I must get out,’ I said firmly and with emphasis. ‘You must open the doors.’

The locks went up.

I got out and squinted in the sun. I showed my identification to the guard, who was young and militaristic.

‘The glass is tinted and I couldn’t see you,’ he said. ‘Next time just roll your window down.’

The driver had started taking my luggage out of the trunk and setting it on the road. He glanced about frantically as artillery fire cracked and gunshots popped from Marine Corps and FBI firing ranges.

‘No, no, no.’ I motioned him to put the luggage back in the trunk. ‘Drive me there, please.’ I pointed toward Jefferson, a tall tan brick building on the other side of a parking lot.

It was clear he did not want to drive me anywhere, but I got back in the car before he could get away. The trunk slammed and the guard waved us through. The air was cold, the sky bright blue.

Inside Jefferson’s lobby a video display above the reception desk welcomed me to Quantico and wished me a happy and safe holiday. A young woman with freckles signed me in and gave me a magnetic card to open doors around the Academy.

‘Was Santa good to you, Dr. Scarpetta?’ she cheerfully asked, sorting through room keys.

‘I must have been bad this year,’ I said. ‘I mostly got switches.’