Emma pretends to be Sutton as she tries unravel Rebecca's lie on The Lying Game. "Catch Her in the Lie" is the seventh episode of the show's second season.
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The Lying Game Season 2 Episode 7 Quotes

Sutton: Trust me.
Rebecca: Well that's just it Sutton, sometimes I'm not sure if I can.

If anyone found out that you know about me and Sutton your life could be in danger.

Emma [to Laurel]