Victoria was the main person responsible for starting it, whether it was out of guilt or as a way to cover her tracks is still unknown.

She decided to steal her mother’s car and go on a joy-ride with Declan Porter instead of attending the gala honoring her mother. 

Lydia was not happy with recent events and planned to make a speech exposing the truth behind Flight 197. Frank got wind of this and informed his boss. Shortly before Lydia went to the podium, Victoria whispered something into her ear. Whatever Victoria said frightened Lydia enough to change her speech. 

REVENGE - "Guilt" - Victoria's more vulnerable side shows through when lingering feelings of guilt over her involvement in David Clarke's demise and an unforgivable rift with her daughter become too much to bear; Lydia returns with a vendetta against Emily and the Graysons that will soon come back to haunt her; Now wise to his father's transgressions and a duplicitous betrayal by his friend, Tyler, Daniel decides to make a major life change; and Charlotte and Declan find themselves in an unlikely predicament together, on "Revenge," WEDNESDAY, OCTOBER 19 (10:00-11:00 p.m., ET), on the ABC Television Network. (ABC/RANDY HOLMES) AMBER VALLETTA