UPDATE 3/19: Pretty Little Liars threw viewers a major curveball with Toby Cavanaugh's (Keegan Allen) apparent death on Season 3, Episode 21: "Out of Sight, Out of Mind." However, in the Season 3 finale we learned that he's actually alive and well, and, according to him, he was not directly involved with the faking of his death.
In the episode, Spencer (Troian Bellisario) tracked him down, only to have him claim that he was on the "A" team to protect her. Is that the whole truth? We want to believe so. So does Spencer. But will she be able to forgive him for standing by while she hurt? They do hook up again, but that doesn't mean all the pain is forgotten.
And, just as importantly: We have to wonder who died in Toby's place. And unfortunately, our best guess is Jason (Drew Van Acker).