The Lallys are a nuclear family, settled in a small town in Kentucky. Peter, the father, is employed at the Kentucky Police Department. Joan, is a stay at home mom who is head of the neighborhood crime watch group (but really she uses it to spy on her neighbors.) The twins, Shelly and  Joey hate each other, but in times of crisis, they pull together. Everything is going swell for this little nuclear family until an alien crashes on their roof. A strange, yet exciting adventure for the Lallys to undertake, they decide to adopt the alien and name him Roswell as if he is one of their own family members. Comical situations soon follow.