Sara's reaction to Poseidon.

As we all know, in episode 7 of season 5, we, the viewers, along with Sara, discovered who Poseidon is. But shouldn't they have explored Sara's character a little more in relation to Poseidon? I mean, this man sent her to prison, poisoned her, beat her, took her husband, her son doesn't know his father, and she's spent years mourning Michael's death. How did he enter her life and gain her trust.

And then there's Sara's reaction. When she discovers the truth, her reaction is quite cold. She's angry that he used her, but she's not heartbroken.