It's weekend. Tim reveals to Al that he is going to put the 350 Chevy engine in his hot rod. Tim has invited "some friends" to help him. Al wants to come too. Tim thought Al would be spending the weekend with Greta (last seen in season 1 episode 21, "Al's Fair in Love and War"). But Greta broke up with him. So Tim invites Al. Karen has broken up with Greg and is visiting Jill. When Tim tells that Dave Gibbons is coming, Jill wants to introduce him to Karen. Tim can see what Jill has in mind and protests - he needs Dave in the garage. Another friend of Tim's, Bob, brings his pregnant wife with him. The next to arrive are Hank and Wanda. And Tim's original plan was that no one bring along their wife. Then Jill gets the idea that they should barbecue...

On Tool Time: Al claims he can distinguish types of wood by their smell, even blindfolded. Tim agrees to set up a test for Al. At home: Brad and Randy decide to build a catapult. Tim has tuned up his weed whacker - with predictable results. Karen and Dave stop by on their way to the opera. Dave asks a favor from Tim; should Karen ask, Tim is to say that Dave was at lunch with him the previous day. He's actually seeing another woman, but doesn't want to hurt Karen.