Lois' estranged parents, Ida and Victor, pay the family a visit. Right away, trouble starts brewing. Victor bonds with Reese, Ida gets Malcolm into a fight, and Dewey is haunted by childhood memories of his inattentive grandparents. To make matters worse, Grandpa Victor gives Reese a live grenade as a present, and worse comes to worse, the boob pulls the pin! Luckily the family survived the explosion, but their brand new, expensive refrigerator wasn't as lucky.