History WMG / TheWhiteChamber

** Actually the artifact might be attracted by the atmosphere.

* Further implied by the final shot of the Artefact whirring away deep in the forest, despite the station having exploded. Sure, it might note have been destroyed even by an explosion, but landing on the same tiny island (and upright, no less) rather than spiraling into deep space? Unlikely.

Instead, he's a composite of all the people Sarah killed. Besides "Arthur", there are four other people she killed. There are six body parts, the head and the eyes belong to the same person[[hottip:*:After the flashback, if you look at the shower, Sarah will say "I think I saw it in his eyes, so I took his", implying she physically removed the eyes]], the torso and the right arm belong to the same person[[hottip:**:Namely, the guy she threw in the fan. Something was "clogging the ventilation", and Sarah had an OhCrap moment and immediately volunteered to go down. She took out the torso with the leg attached and the severed right arm (the rest had been messily butchered into LudicrousGibs) and hid it in the room. That room doubled as a kitchen, and the torso fit in that fridge nobody used anymore, so...]], so there are four sets of body parts that do not belong to the same person - what a coincidence. Also, most of the flashbacks at the end take place in the places you find the body parts, and the ones that aren't are easily explained. The ventilation flashback is explained in hottip 2, and the cradle flashback was near the beginning, so Sarah could have had enough sense to dump the body into the freezer to dispose of the evidence, and the flashback ''does'' show Sarah dragging the body away.. Also also, "Arthur's" monologue talks about "what you did to all of us" and "''We'' have reached a verdict", implying he was not one person. The tapes and the killing-Arthur flashback can both be easily explained as the Artefact (and the corresponding dead people's souls) freaking with your mind. So, you spend most of the game running around building the single physical avatar of the dead crew, dubbed Arthur, out of their body parts so they can tell you why this is happening to you, and why they're all getting their revenge. This explains everything.

Sarah didn't murder the crew members. Arthur is a sadistic CompleteMonster and traps her in the simulation in order to torture her psychologically. Her "memories" of killing the crew at the end are induced by the Artefact as well, and her belief in her guilt shows the final slippage of her sanity.