RE Silas/Mercedes
Spoiler:
I don't think he will kill her in that vault because of the baby, he will just scare her for revenge about what she did to Riley but she matches his killing criteria indeed.
There is a Halloween fancy dress party in Chez Chez so I think he'll kill someone on that day whilst Mercedes beforehand is trying to escape to the village to warn people. I think there will be a mix up with costumes and he will kill the wrong person e.g. Heidi

.
That is my theory about what might happen.
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Champions 2013! #20
Thanks for everything SAF- Legend!
Proud HHH fan- TIME TO PLAY THE GAME!