The moms are going through exactly the same thing. Making accusations, snooping around in other people's homes, getting locked in, trying to find a way out and sharing banter no matter what they're doing.
They went down to the basement because they thought Kenneth was down there. Then Ashley comments: I think there's something rotting down here. I think Daddy Dilaurentis IS in the basement BUT in the words of the great Randy Meeks - "His body will come popping up in the last reel somewhere!"
remember the halloween episode in season 4 (Grave New World) the girls are going into the passage way under the cemetery kinda looks like the basement scene here
I think they should have done the older mom's actresses when they were teenagers through adult life instead this version of the young actresses stars that will be awesome ever