"Tracker. That’s not it. Gel cap around it, makes it less easy to lose, easier to swallow. Barely big enough to see, on its own. Ash ordered them from Belgium. Bonds to your stomach lining, good for six months, then it disassembles itself and nature takes its course. Company makes it has its own string of low-altitude satellites. Have to keep putting ’em up, but they make that a feature, not a bug, ’cause they get to keep changing their hardwired encryption."