The shapeshifter is not the woman walternate was having the affair with in season three right? Someone suggested it but I'm thinking no. Would be interesting!
Michelle Krusiec plays Nadine Park (the shapeshifter woman from Neither Here Nor There). She is not the same actress as Walternate's mistress in season 3.
"Into each generation a slayer is born.
One girl in all the world..a Chosen One."
Dabbling In Fringe Science
I was thinking the same thing...