Celia comes down with the chicken pox, and having never had it herself, Gabrielle must keep her distance, so she stays with Bob and Lee for a while, and is suddenly reminded of what it feels like to be "single" again. In the meantime, Tom and Lynette forget little Penny's birthday, which leads the girl to go missing. Bree hires a promising new employee (guest star Sam Page) and Katherine makes a surprising discovery about herself. Meanwhile, Susan cheats on Mrs. McCluskey, whereas Angie grows concerned over Danny's disappearance.