I liked it - the whole physics/time travel angle is up my alley (though I have no idea if it is remotely possible since I'm not an astrophysicist). But I don't know if it's because it's the abridged audiobook or it's how the actual novel is as well, but it just felt like it was building up to the ending and it just ended, wrapped up and that was it. But still, all in all, pretty good - especially since it was mainly a Spock and McCoy working together story for a good chunk of it - always great to see them together.
mass market paperback, 224 pages
Published Jan. 5, 1981 by Pocket Books.