@B0rked_Gamer - I've just watched the season opener and my guess is:|
Doctor Vogel likely knew Harry. If she had the drawings Dexter did then maybe she was treating Dexter as a child? I don't see why she would have the drawings otherwise and she is a 'neuro-psychiatrist specialising in child psychopaths' according to the Wikipedia Dexter Season 8 page. It would fit and Dexter wouldn't necessarily remember who she was if he was only young at the time (I'd say 5-8 years old from the drawings). Maybe she was the one who gave Harry the code in the first place?
It was great to see Dexter back but he seems to be heading down a slippery road to his eventual demise I think. He was a lot less likeable as person in this opener; he lost his temper at least three times and almost slipped up twice.
PS3, PS4, PS Vita, Wii U, Xbox One, PC (Intel Core i7-4770K, 16 GB, 4 GB EVGA NVIDIA GeForce GTX 980 SC, Windows 8.1 Pro), 128 GB iPad Air 2, 128 GB iPad mini with Retina Display.