THIS OLD HOUSE welcomes Edgar Hansen from Discovery Channel's "Deadliest Catch." To assess his skills, Tom puts Edgar to work patching cracks in the plaster walls, then Richard shows him how to "fish" water lines through the building. Norm and Tom raise the height of the railing on the second floor landing. Roger and Edgar remove the concrete stairs at the front entry. In the second half of the hour, on ASK THIS OLD HOUSE, Roger visits Biloxi, Mississippi, where he builds a high tunnel greenhouse with a homeowner. Richard explains the best types of pliers and wrenches. Electrician Scott Caron converts three recessed lights into three pendants in a kitchen. And the guys ask, "What is it?"