I don't take to the George storylines - I don't like gangland stuff and had been hoping it didn't take hold. Much preferred the earlier series, and the crime/police/detection aspects (inc how far can a cop go)
What happened to Mary btw?
I think the brain tumour is in the head of the she-Lake. My theory - they've been at the pointy perversions together for years (on patients? wonder what the 'suicide' rate for her psych patients was), and she's been the strong one, keeping it under the radar by enforcing agreements/boundaries.
She is worried that as her cognitive functions change, she will not be able to control him, and that if she becomes incapacitated he will be out of control unless he learns to self-impose limits (which hitherto she has externally imposed). She is already more tired and intervening less, but still teaching and reminding him of the agreements (boundaries) and why they work.
He looks strong/active, but is really very dependent on her. And can't bear the thought of being without her (needs her to control him). So wondering if fridge-woman (taken without she-Lake's prior knowledge/consent) was pretty much what it said on the tin. Convinced no other woman could love him spontaneously (fair point, given his murderous history) or care for him as she-Lake does, he wanted to force one to, via kidnap/brainwashing/Stockholm syndrome.