There’s nothing to suggest that Jessica wasn’t simply part of a shipment of children, raised by her scientist ‘father’ in the same way that Dale was given twins Charlotte and Lily to raise as his own. However, there’s a chance that she could be her father’s biological child, and if so, there’s also a chance that Milner is her biological mother (though at this stage, we’re only in the realm of mad speculation.) Arby does call Jessica his sister, but presumably he’s talking figuratively in light of their shared childhoods as lab rats.
Why did Arby/John betray The Harvest?
‘Every child needs love, I think’
Because he read the Utopia pages he’d taken from Grant, and realised that The Harvest had subjected him to experiments as a child that turned him into an unfeeling monster able to commit brutal acts without feeling remorse. Arby (a modification of the initials R.B, which stood for Raisin Boy, the name the Harvest scientists gave him because of his fondness for chocolate-covered raisins – he didn’t even have a name) realised that Harvest had mistreated him, and so decided to choose his own name – John – and his own purpose: to help his ‘sister’ in experimentation, Jessica Hyde.
Why was Wilson Wilson with Thomas and Christie in the end?
‘Everything I do is a cure for our current situation.’
Because (unless he’s playing the double agent game) Wilson Wilson had come around to Christie’s way of thinking, and so betrayed the group. As its most fringe member, and a believer in conspiracy theories, Wilson felt that Christie was right about global overpopulation (remember his frustration about Dr Mike and the rich oligarch whose house they crashed at having too many belongings?). Wilson, we can assume, has now joined The Harvest as one of Christie’s followers, despite The Harvest having murdered his family.