Kit left Tom s by use of another transit spell, one that let him out in a sheltered spot by the town library. He spent a while there Web surfing, printing out what he d found, and then located a few books and checked them out. His mother was up when he got home, showering; by the time she came out, wearing her bathrobe and drying her hair, Kit was lying on the living room floor with papers and books all around him. His mama paused, looking over his shoulder at one of the printouts he was reading.  Autism   she said.

 Yeah.

She headed past him into the kitchen to find her big mug, filled it with the coffee that Kit s pop had left in the pot for her, sugared it, and came back in to sit down on the sofa behind him.  Big subject, son,  she said.

 You know much about it 

 Enough to get by. She drank some coffee.  There are a lot of different kinds, and we re still feeling our way around to the causes. Once they thought autism was caused by being raised wrong, by having parents who were cold or abusive. That theory got thrown out a long time ago. But there are still a lot of possible causes, and some of them seem to include each other. Some autism may be too little of one chemical or another in the brain. Or it may be caused by an enzyme that s missing, so that certain chemicals build up in the nervous system and damage it, or make it behave erratically. It may be caused by something wrong with the immune system, or rogue antibodies that attack brain and neural tissue, or even a virus, or pollution, or vitamin A deficiency   She raised one hand in a  who knows  gesture, then let it fall.  There re a hundred answers, maybe all of them right sometimes  Is this for school 

 No. It s what Tom wanted to see me about.

His mama s eyes went wide.  Yourmissing person  He s autistic  Oh, honey, that sterrible! His parents must be heartbroken. Do you think you re going to be able to find him