Across the Arizona Desert: Continuing Along the Shortest Route, originally Mrs. Robinson in the WSJ release, is the seven hundred sixty-sixth chapter of the JoJo's Bizarre Adventure manga. It is also the fourteenth chapter of Steel Ball Run.
Summary
In the middle of the desert, Johnny and Gyro argue about the Italian's poor sense of orientation while they are followed by Mrs. Robinson from a good distance. Suddenly they are attacked by cholla's thorn, the chollas being cacti which propel their thorns at high speed with the faintest stimulation. The duo understands that Mrs. Robinson is attacking them somehow and try to flee. Johnny is then unhorsed and badly hurt by chollas thorns, prompting Gyro to confront Mrs. Robinson. Mrs. Robinson attacks Gyro with the chollas, using insects he breeds in his eyesocket to stimulate the cacti, but the Spin's vibration allow Gyro to control the chollas too, and every cholla in the vicinity propels their thorns toward Mrs. Robinson, defeating him.
Some time later, Mountain Tim investigate Mrs. Robinson's horse which is revealed to have a different horseshoe than the murderer, meaning he is still roaming in the Arizona Desert.