Chandra observations of the core of the nearby starburst galaxy NGC 253 reveal a heavily absorbed source of hard X-rays embedded within the nuclear starburst region . The source has an unabsorbed , 2 to 10 keV luminosity of \geq 10 ^ { 39 } erg s ^ { -1 } and photoionizes the surrounding gas . We observe this source through a dusty torus with a neutral absorbing column density of N _ { H } \sim 2 \times 10 ^ { 23 } cm ^ { -2 } . The torus is hundreds of pc across and collimates the starburst-driven nuclear outflow . We suggest that the ionizing source is an intermediate-mass black hole or a weakly accreting supermassive black hole , which may signal the beginnings or endings of AGN activity .