Revert vertex position to Basis Shape Key How I can revert the position of a single vertex in a shape key to it's position in the Basis Shape Key?
Use Blend From Shape:


Select all vertices whose positions you want to reset,
Execute Blend From Shape, accessible from W, Ctrl-V or Mesh > Vertices menu,
Set "Basis" as shape key to blend from (by default),
Set blend factor to the maximum value 1.0 (by default),
Uncheck Add, so only values from "Basis" will be blended in, effectively reverting all selected vertices' position.