Why was Dan already at Charles' house when Vincent arrived?
I know that there are many details in this series that seem mysterious (you really need to watch the episodes more than once to take everything in), but one thing that I cannot understand is why Dan was already in Charles house when Vincent arrived, and how did he get in. Did Liam leave a door open? When Vincent arrived, all the doors appeared locked (Vincent had to get a brick to smash the terrace door and get in), and yet Dan was already inside. Did Dan enter the house at the same time as Vincent but through another door? Otherwise he would have seen Charles seemingly dead on the floor and would have known that Vincent didn't attack him (and why didn't Vincent protest a bit more?). And, as someone else has remarked, how could a polar bear have entered (and and got out!)?
Why did Dan go there anyway? And wouldn't he have seen Liam?
This whole scene needs explaining. Can someone do it?