Shades of Grey — Clea Simon

It's getting hot and sticky for Harvard grad student Dulcie Schwartz, who's doing temp work for an insurance agency while struggling with her dissertation on Gothic villains. To make ends meet, she sublets to a new roommate, a ladies' man who winds up stabbed to death on her living room floor. Then she starts seeing a strange cat about -- and begins to think it's the ghost of Mr. Grey, her beloved late pet, warning her of danger.

Dulcie really starts to sweat when she is accused of sabotaging her employer's computer system and she's fired. Soon after, someone hacks into the Harvard system. Police decide she's a "person of interest" on all counts. Desperate for answers, Dulcie uncovers cryptic messages buried in her computer, warning her to be careful. Are they from her dead roommate...or someone else? More frightening still, is the killer now after her?