Pete's reaction to H.G. through most of "3...2...1" reflected my view of her and how the writers ultimately decided to portray her in the season finale. For most of the second season, H.G. was perfectly fine and a likable character, but the writers decided to make her batshit crazy and out to destroy the world. This was utterly baffling and was, quite frankly, a stupid way to create drama, manufacturing drama and action from a situation which showed little signs of anything wrong.
I'm not sure if "3...2...1" truly redeems H.G., considering just how illogical and devious she was, but it at least made me feel sorry for her. We see her in her heyday, when she an inventor, expert Warehouse agent, and master storyteller--all contrasting with the bronzed H.G. we see at the end of the episode. She truly has fallen from grace and her words in the episode indicate remorse. Taking that on face value, it seems like H.G. isn't totally crazy. But then again, the writers could also make it so that she's fooling everyone again.
The episode cleverly ties together three timelines with all the agents tracking down Joshua's horn. We get to see Jack and Rebecca again and see them agree to have a full-blown relationship. H.G.'s plot, set in late 19th century London, was the highlight of the episode, giving us her background and showing us how awesome she was. Syfy announced a spin-off some months ago revolving around H.G. and if this episode is indeed a precursor to that, or even a backdoor pilot, then I'm definitely in--as long as the writers avoid the part about her being crazed and wanting to use the trident.
Score: 9.0/10