Throughout the week, the lives of three families continually intertwine as each one engages in day-to-day activities. Meals, after-school classes, caring for pets, grocery shopping and gardening all become communal events in this urban neighborhood, as friends and family members look out for each other and share their ups and downs. The story opens on the title page with framed portraits of the three families -- that's the last time we see them as separate units. As the story progresses, we see children, parents, grandparents and pets in and out of each other's homes and lives. Ormerod's detailed pen-and-ink and watercolor illustrations depict the daily hubbub while her lively text describes the action and invites children to interpret what's going on by asking questions that begin with the word "who?" The delightful visual complexity will encourage repeated readings and observant readers may eventually have more than one answer for the question posed by the book's title. (Ages 3-7)