There has been much speculation over the motivation of Mr. C throughout this season -- what is his goal, where is he going, and why.
It's worth pointing out that when Mr. C showed the modified ace-of-spades playing card to Darya early on in this season he indicated that it was something he wanted. For the record, I'm fine with never finding out what the symbol on the playing card represents. I will suggest, however, the following: given that the portal near Jack Rabbit's Palace had been seemingly calibrated by him to lead to the Palmer house (before Fireman adjusts it to lead to the Sheriff's Station) it is not unreasonable to associate whatever the playing card represents with the Palmer house -- or resident(s) therein. Without even having to mention Judy at all, we can guess that whatever darkness lies behind Sarah's face and in her inhuman wails has some connection with the playing card symbol that also appears on Hawk's living map. We don't know why Mr. C wanted to find it or what he intended to do once he had found it, but we at least know where he was headed and how the thing he was after was symbolised, and that is something.
As a matter of fact, 'Chalfont' was the name of the people that rented this space before. Two Chalfonts. Weird, huh?