da Marie Twist is an inquisitive African American second grader and a born scientist. She possesses a keen yet peculiar need to question everything she encounters, whether it be a tick-tocking clock, a pointy-stemmed rose, or the hairs in her dad's nose. Ada's parents and her teacher, Miss Greer, have their hands full as the child's science experiments wreak day-to-day havoc. On the first day of spring, the title character is tinkering outside her home when she notices an unpleasant odor. She sets out to discover what might have caused it. Beaty shows Ada using the scientific method in developing hypotheses in her smelly pursuit.