Doctor Lesko

 is a scientist living in Grayditch in 2277.

Background
Lesko created the Fire Ants that carried off or killed almost everyone in Grayditch. He was experimenting on giant ants, trying to return them to their normal size through genetic manipulation when he accidentally created the fire ants. Despite the death and destruction his experiments caused, Lesko has remained indifferent to the lives lost, stating, "At the cost of a few, generations shall be saved".

Lesko has a shack by the diner which requires Average Lock-picking Skill, or the key to enter. He can be found deep underground in the Marigold Station. He is involved in the quest Those! which can be obtained from him or alternately you will be approached by Bryan Wilks who will trigger this quest, Doctor Lesko's quest offers either Ant Sight or Ant Might as a reward, the player can choose between the two.

Appearances
 only appears in Fallout 3.

Behind the scenes

 * Lesko may be named after "James R. Lesko", a character from the film Phase IV, who is also a scientist who has to deal with "Ant Problems".
 * If Lesko turns hostile, he may shout "I will blind you with science!" - a possible reference to the Thomas Dolby song, "She Blinded Me With Science".
 * Dr. Lesko might have been inspired by the Simpsons character Professor Frink, since both of them are scientists and mostly makes things worse with their inventations. They also sound the same.