A case study of considerable curiosity and fascination- over and above its clinical interest- was originally presented in shorter form in the Journal of Abnormal and Social Psychology, and now appears with a wider audience in view. It is that of Eve White, a multiple personality- and the tragic consequences to which this rare disturbance led. A quiet, unspectacular, delicate figure when she first came to Drs. Thigpen and Cleckley for help- Eve was also a devoted wife and mother and the victim of headaches and blackout spells. As longer periods of amnesia occurred, she took on the identity of Eve Black, extravagant, carefree, coarse- given to irresponsible actions which were to humiliate the other Eve on her return to that identity. In time (and after hospitalization, hypnosis, psychotherapy) a third personality was to come ""out"" more and more frequently, that of Jane, the most balanced of the three, and it is Jane- after the ""deaths"" of both Eves- who offers the most hopeful (but not definite) future..... A perplexing psychological phenomenon, which poses many ""human, therapeutic and theoretical issues and which is documented- without doctrinal bias. The publishers will lend their promotion.