Carrie didn’t try to remind her that she hadn’t lived at home for twenty years now. Carrie’s mom suffers from dementia, which is progressing rapidly. Mary Keene, who was a respected surgeon at Middleton Hospital, who saved literally thousands of lives in her career, who once knew the entire anatomy of the human body and the name of every structure and organ, now gets lost on her way to the bathroom. She noticed her deterioration in time to surrender her license — she was mostly retired anyway — but only just barely.

The doctors say it could be Alzheimer’s, or it could be vascular dementia, or a series of small strokes, or possibly a large one, or some other progressive deterioration of the frontal lobe. But they also say the specific diagnosis doesn’t matter because it will not change anything. None of it is treatable. Carrie’s mom is drifting away, a little further every day. In a few more months, or a year at the most, she will be gone.

The irony is not lost on Carrie. The girl who can’t forget has a mother who cannot remember.

Her father said they’d talk later. He was upset with her, because it would take that much longer to get her mom to the car.

Or he was upset with her because she was back home. They get along at Thanksgiving and Christmas, but she and Mike Keene haven’t really been close since Carrie cost him his job as chief of police.

So, left to her own devices, Carrie found the keys to the Metro and went to work on another mystery, like when she was a kid.

She started with the only clue she had, aside from the symbol drawn in blood: the invitation.

Carrie didn’t recognize the writing on the back. And despite what the CSI shows tell people, handwriting analysis is only slightly more accurate than phrenology. Block printing is still pretty much untraceable, even to someone with FBI resources.

But Carrie recognized the handwriting on the envelope, which was different. She remembered the time in high school when Hailey Thomas asked Carrie to recover her diary, stolen from her locker. Hailey was the head cheerleader, on the student council, and queen of the mean girls.

They weren’t friends; Carrie wasn’t in school to make friends. She’d been busting her classmates for every minor infraction since kindergarten.

Still, Hailey begged and pleaded for Carrie’s help, and it only took a few minutes of searching. (It was stashed in Wade Wellman’s second-best hiding place, a hollow under a bottom shelf in the school library, along with a baggie of weed and some porn.) And Carrie got to read it. There was stuff in there that Hailey would never want made public, like a detailed account of the first time someone went down on her (it wasn’t her boyfriend; it wasn’t even a boy).