Recently, we talked about animal uplift stories, where non-human creatures gain human-like intelligence. Well, there's a subclass of that genre: the smart cat book. Every kid goes through a cat phase, and there's no shortage of scifi books that pander to this obsession. There are cat familiars, the Kzin of Larry Niven's universe, and clans of warrior cats like those in the Warriors series. But for the best scifi cat wondrousness, combined with gritty, realistic setting, you can't beat Star Ka'at by Andre Norton and Dorothy Madlee. I think I wore a hole in that book when I was a kid, dreaming of powerful, psychic cats coming to Earth to rescue me. And this mid-70s book holds up over time.
It's the tale of two orphaned kids, Jim and Elly Mae, whose lives on Earth are verging on hopeless. Jim lives with crappy, abusive foster parents and Elly Mae collects junk on the street to sell so she can buy food for her dying grandmother. Sound depressing? It is. Their lives start to look up, though, when they meet Mer and Tiro, two Ka'ats who have come to Earth to rescue their fellow aliens from a "disaster" that we assume is nuclear annihilation of the planet. Apparently many cats on Earth are related to the uber-intelligent alien Ka'ats, but only some have retained their mental acuity and others have gone native. The Ka'ats psychically bond with Jim and Elly Mae, helping them deal with Elly Mae's grandmother's death and eventually adopting the two children as "kin."
If you know an imaginative kid who loves cats and wants to leave the planet, try Star Ka'at out on them. The sequel, Star Ka'at World is terrific too.