When a little boy sees a cat slip into the open door of an apartment building, the temptation is too great: he follows the cat into the lobby. Before continuing up the stairway, the boy picks up one of several discarded drawings that litter the floor. Another open door awaits. Again, the boy follows the cat, this time into an apartment filled with books and toys. No one is there, but a table set for tea testifies to the fact that...