To most of us the word "Cambridge" means Whole Foods and Harvard, or funky shops on Mass. Ave. But to author Sam Baltrusis, Cambridge means a lonely British soldier from the Revolution, forever wandering the pews of Christ Church looking for his brothers-in-arms, or Dr. George Parkman, a Harvard professor brutally murdered in 1849, whose restless spirit still lingers at the site of his death. Join us this Thursday 7 p.m. at the Central Library when Baltrusis reads from his book The Ghosts of Cambridge, sharing these and other stories, immersing us in the dark side of local history. The chills continue on Wed. Oct, 16 when Renee Mallett reads from her book Haunted Colleges and Universities of Massachusetts. Mallett will share eerie stories like that of the grief-stricken widow whose ghost wanders the halls of Endicott College and explain why BU students think they sometimes see the spirit of Eugene O'Neil. The scary gets wicked local Sunday, Oct. 20, at Milk Row Cemetery with The Ghosts of Somerville: Up Close and Intimate. You'll go grave by grave and learn why the occupants don't always stay put.