Paralyzed individuals control prosthetic limbs and wheelchairs with their minds. People with devastating neuromuscular disorders can now communicate or make art. Innovations in brain-computer interface (BCI) are making the impossible, possible, and transforming our understanding of the brain’s capacity to adapt and function. From patients to athletes to artists, these remarkable scientific and medical advances are changing lives and the ways we engage the world but also present new ethical and legal considerations that must also be explored and understood.