Madeleine, by Amal El-Mohtar

Madeline is my first read in the Nebula Short Story category this year.  And it's a nice fun one.  A woman who participated in a drug trial has extremely realistic flashbacks to earlier periods of her life, in which a stranger appears to her.  Anyone who remembers the 70's has a decent chance of having had this happen to them.  OTOH that leaves out a lot of people.  So it is at least a little fresh again.  Give it 3 stars for being nominated.