When a small spaceship carrying six alien babies lands in Ava's backyard, she is presented with a mystery. The spaceship is packed with cribs, blankets, and bottles... but why would parents send their babies alone through space? As she is looking up at the stars, she shares a startling realization with her brother Joe: "Something dangerous must be up there. I can't think of any other reason parents would send their babies away, except to protect them from danger. To save them." Joe, who laughs at danger, comes up with one theory after another about what the danger could be. The aliens' sun might have been getting too hot, or their planet might have been about to explode, and they launched the little spaceship just in the nick of time. Soon he convinces himself that "some very bad aliens were after these babies and their parents." Not only that, but Joe also decides that the bad aliens are already on their way to Earth! Joe's logic is that the bad aliens must be more powerful than the good aliens, since the good ones are afraid of the bad ones. He tells Ava, "If the good aliens are smart enough to come here, the bad aliens must be, too. I bet they have a big space map with a bull's eye right on top of our house!" While Joe prepares to protect the babies from the invasion of bad aliens that he is sure is coming, Ava is more concerned with protecting them from Earth-based threats and raising them well. The babies learn fast: by their third day on Earth, they understand what is said to them, can talk, and can run! Taking care of the six little aliens helps take Ava's mind off some big-time stressors. Ava realizes that her problems are small compared to those of the little aliens. When Joe is attacked by another spaceship just a few days later, his attack makes his theory about bad aliens look frighteningly accurate. To make matters worse, those first two spaceships are from the last ones that will land in Ava and Joe's backyard!
