The mystery deepens. Caprice Fimbres McIlvaine, formerly head of internal communications at Hewlett-Packard (HPQ) and a top aide to ex-CEO Mark Hurd, has left the company, following her boss out the door three days after his departure. Her exit is significant because, according to two people with knowledge of her former role, McIlvaine was the key conduit in hiring Jodie Fisher, the actress-turned-corporate hostess/”marketing contractor” who later filed a sexual harassment suit against Hurd, setting in motion the chain of events that resulted in the CEO’s resignation on Aug. 6. McIlvaine resigned effective Aug. 9, HP confirmed Wednesday.

McIlvaine occupied a unique role at HP. Originally hired to work in the company’s corporate communications group, she ultimately rose to head internal communications for the company as well as serving as something of a chief of staff to Hurd. She typically was one of the few people who accompanied Hurd on trips away from company headquarters, arranging meetings, lodging and the like.

Importantly, McIlvaine organized the gatherings of top customers — dubbed CEO Summits — at which Hurd spoke and Fisher acted as a greeter for those customers. What precise role McIlvaine played in hiring Fisher couldn’t be learned. It is unusual at HP, or any large company, for a series of top-level gatherings to be coordinated by the office of the CEO, as opposed to a corporate marketing group that does this sort of thing frequently.

McIlvaine is 37 and worked at HP as the “CEO program manager,” according to her LinkedIn profile. The profile does not say what year she joined HP but indicates that she left her last employer, PR agency Blanc & Otus, in 2004. Hurd joined HP in 2005, following the firing of the company’s previous CEO, Carly Fiorina. Attempts to reach McIlvaine for comment Wednesday were unsuccessful. Fisher’s lawyer, Gloria Allred, did not respond to a request for comment. A spokesman for Hurd declined to comment.