It's not until halfway through the mini series that we get a glimpse at Montgomery's past and how she got to where she is today. It seems she has her own duplicitous investor, a man known only as Liam. He exists as a dark force of influence over Montgomery. He claims that he made her what she is. He gave her money, connections, and a purpose. He seems to be the only one that can get under her skin. Montgomery was an intern at a London bank when Liam found her and made her an offer she couldn't refuse, much like she made to Sean and Lisa. He wanted to exist in the shadows, but still be able to invest in fortune. Montgomery would do that for him. Since then, she has fallen into an all-consuming obsession with how people justify gratifying their true desires.