From trolley tours and haunted mansions to classic horror flicks, trunk-or-treats, and moonlit hikes, October on the South Shore is filled with ways to celebrate both fall and fright. This year’s lineup blends local flavor with seasonal fun – a beer-lover’s crawl through Quincy and Braintree, a spooky candlelight concert in Plymouth, harvest-season mazes in Plympton, and family festivals from Hanson to Scituate.