Fake dating profile experiment
When they tried to kill Catherine, she ran into the woods but tripped and fell.
Suddenly, the two gunmen were attacked by what Catherine described as a "beast." No one believed her, though, and she believed them when they said she was just traumatized.
The two makes plans to meet up again, but before they can get away, Catherine finds out the reason Vincent has been distant from her is because he's been having blackouts, during which he can be violent and can't remember what happened. Vincent later calls her over when he has a flashback that reveals Vanessa was in Afghanistan, and part of Muirfield.
Catherine is around when Vincent finds out she's not the trigger, and the blackouts are actually a side effect of the experiments.
The same mysterious beast saves Catherine again, and Catherine finds out the "beast" is actually Vincent.