1 part Complete Tess Wilson is at it again! Only this time, the Halifax tween is chasing a ghost from her mother's past. While her parents are in New York trying to enjoy a second honeymoon, Tess and her brothers are left home under the watchful eye of their Grandpa Lou. It's also Halloween! Angered that he has to ditch plans with friends to stay home and dole out candy so his grandfather can mind the revelers in his South End neighborhood, Tess's older brother, Danny, taunts her with spooky tales of a witch's den and dire warnings not to enter a notorious, run-down, backstreet passageway called Tin Can Alley. Naturally, Tess takes the bait. Under the guise of trick-or-treating, she seizes the opportunity to investigate the aforementioned and stumbles on to a crime scene that's been hidden for over 40 years. But when she learns the shocking truth that the victim was a child like herself, anxiety threatens to thwart her investigation. Thankfully, she's not alone. With the aid of her grandfather; his rat-pack group of coffee drinkers; her quirky aunt Izzy, gifted in the art of séance; and of course, her BFF, Chucky, Tess works to unravel the mystery, which also includes stolen church money, a tragic suicide and a spiteful pigeon lady. Meanwhile, Tess's mom, Alice, is fighting her own demons south of the border. As she follows her daughter's investigation from afar, she's haunted by memories of her own childhood. Flashbacks to Tin Can Alley and horrific images of bearing witness to a murder keep popping up in the most unlikely places. And while Tess's dad, Sam, tries to run interference to his wife's mania, it's a losing fight when all Alice wants to do is return home and put an end to the madness that has brought them all to a dead end.