When Emma sees the empty cell, she asks Henry what he's done. Henry swears Mary was already gone when he arrived. Gold exposits that her arraignment is tomorrow. Emma has to find Mary and bring her back before anyone, especially Regina, realizes she's missing. As a fugitive, Mary is "screwed" even if she's not convicted of Kathryn's murder. Emma tells Henry to go home. He whispers, "If she leaves Storybrooke..." Emma not-nows him. She's only got until 8:00 AM to find Mary. Gold reminds Emma that if she's caught helping a fugitive, her own future is in jeopardy. Emma says she doesn't care. "I'd rather lose my job than my friend." Gold's expression is opaque as he watches Emma leave. Once she's gone, he turns toward the empty cell.
Outside, Emma hops in her yellow VW Bug. Cut to a shot of her speeding down a foggy, forest road. She sees a man walking, but is driving so fast, she has to swerve to avoid him. He's startled, too. When he jumps out of the way, he falls down a small embankment. Screeching to a stop, Emma jumps out and is all apologies. When she asks the man (Sebastian Stan) if he's okay, he says he thinks so. He's not used to seeing cars on that road, so late. He recognizes Emma as the sheriff and asks her what brings her out in the middle of the night. Emma lies that she's looking for a lost dog. The man wishes her good luck in her search and starts off. When Emma notices he's limping, she comments on him being hurt. The man says, "No, I just twisted my ankle, I think." He lives a mile down the road and can make it home on his own, but Emma insists on driving him. He thanks her, offers her his hand and introduces himself as Jefferson. Emma shakes his hand and says, "Emma."
Sidebar: We'll later learn that Jefferson's limp is fake. This brings up questions about Emma's ability to detect lies. I think there are a few too many things going on, which explain why Emma doesn't catch on. When she asks him if he's okay, he says he thinks he is. That's not a lie. When she later says he's hurt, he says, "No." That's not a lie. He does say he thinks he twisted his ankle, but he took a hell of a tumble (or dive), so he may not be lying about twisting body parts. The limp is a wordless lie. That said, he's saying he is fine and acting like he's not. If Emma's inner polygraph machine is spiking, she likely thinks the lie is him saying he's okay. Mainly though, I don't think she's using her ability, right now. She's too worried about Mary and too hopped up on adrenaline from nearly hitting a pedestrian to hone in on Jefferson. That's my story and I'm sticking to it.