Anyone who has spent decades in public education is aware of the pendulum swing of ideas, strategies, and policies that can cause drastic changes. Since the 1980s, inclusion of critical thinking development in classrooms has sharply declined, given accountability mandates and legislation such as No Child Left Behind. A potential reawakening to critical thinking in classrooms can be spurred by two key reform efforts--the teaching of "21st Century Skills" and the adoption of the Next Generation Science Standards--that both maintain critical thinking skills as foundational. By explicitly targeting these efforts in instruction, teachers from one school district are transforming classrooms into places that foster critical thinking. Through the use of a vignette in which a high school biology teacher helps students gain self-regulation skills while reviewing their knowledge of evolutionary concepts, this article focuses on teacher learning and proposes one way to help the pendulum swing back.