Host Kevin O'Connor arrives to find the floor and walls of the new entry addition framed up, and general contractor Tom Silva getting ready to create the connection to the main house. He lends a hand as they frame up the new roof that will overlay the existing roof. Mason Mark McCullough returns to repair the exterior chimney that was cut away to make way for the new family room addition. Mark shows Kevin how to weave in the bricks so they look like they've always been there. Homeowner Joe Titlow shows Kevin why he wants the hulking fireplace and chimney gone from his kitchen, and they get to work removing it from the top down, brick by brick. Master carpenter Norm Abram revisits the oldest This Old House project to date, the Acton Project, to see how the addition there is holding up after 17 years, and what they'd do differently if they could do it all again. Back at the project house, Kevin and Joe check out some recent discoveries from the jobsite—musket balls, sleigh bells, ox shoe