The repair mission for the Hubble space telescope, as astronauts try to fix crucial equipment that was not designed to be repaired in orbit; common backyard birds with a dark secret, and a clue that might unravel the most brutal reign of terror in the avian world; a profile of neurosurgeon Alfredo Quiñones-Hinojosa;  and studies on the brain of an epileptic to try to understand more about the link between brain structure and memory.