Frederik Pohl returns to novels with another story set in the future universe as gateway, one of his earlier novels. In this an asteroid is discovered in the solar system containing thousands of small spaceships that can be flown to pre determined destinations. All of which leads to contact between humanity and the aliens who built it, the heechee. Gateway is an excellent book and if you've never read it then you should redress that fact at once.
This is what they call a 'fix up' novel, which means that several short stories have been combined, with new linking material, in order to form a novel.
It's compelling for the first sixty pages, as it tells the story of one young gateway prospector and his attempts to find love and fame out in space. But after that the novel loses direction. It's very obvious that this is a fix up novel, as there are several lengthy interludes which introduce other characters where quite frankly little happens.
It attempts to have an overreaching plot with a minor character from the second gateway book trying to get revenge on those who wronged him. But in the end, a myriad of characters are drifting round the galaxy not doing very much, the threat is resolved quickly, and it returns to being the main characters story. And that, by the end of the book, isn't as interesting as it started out being.
Not one of his more memorable works. And that's a shame