They didn't see the reinforced frame. They didn't notice the first-aid kit mounted like a saddlebag or the discreet radio antenna coiled near the seat. They certainly didn't see the way Sarah's eyes moved—constantly scanning, cataloging, remembering.

The sun hammered down on the cracked asphalt of the boardwalk, baking the salt spray into a sticky film. For most, it was a day for ice cream and shade. For Sarah, it was a shift.

A group of teenagers jaywalked between booths. Sarah leaned, the trike responding instantly, and she inserted herself gently between them and a stroller. "Heads up, folks," she said, her voice calm but carrying. "Crosswalk's twenty feet that way."