The rebirth of Lewis

An evil form took over the body of Lewis but it was killed in its previous incarnation. The aliens were displeased and abducted the corpse to implant a brand new soul into it, then returned him to Earth. This new form is a new creation. It looks and sounds like the Lewis we once knew, but has none of the memories, none of the personality traits of the previous one. It is like a newborn infant we must guide and teach the ways of the world. Few people are given a new beginning with the world still remembering the old. People who hold the previous memories against it quickly realize it is something different now.