Darlene struggles to cope with the stress of construction; and after a serious accident, she reevaluates everything and makes a life-changing decision. Elsewhere, Lou, a familiar face from the past, returns as Mark's combative contrabassoon teacher; but after he butts heads with Mark, Dan steps in, only to realize that their similarities may outweigh their differences.

The Conners gear up for a megawedding! Jackie and Neville, Darlene and Ben, and Harris and Aldo are planning for a shared big day, but along the way they discover that some of the couples may not be on the same page about their happily ever afters. Meanwhile, Dan and the family have decked out the house for the occasion, but will all six of the lovebirds make it to "I do"?