Mrs. Frisby, a field mouse with a problem, is befriended by a group of superintelligent laboratory rats and manages to save their lives. John Newbery Medal, 1972. Boston Globe Horn Book Award Honor Book, 1971; National Book Award finalist, 1972. O'Brien's daughter, Jane Leslie Conly, has written two sequels entitled Racso and the Rats of NIMH (Harper, 1986) and R-T, Margaret, and the Rats of NIMH (Harper, 1990). Outstanding Quality.