This pulls together the Rift War! comic story published originally in issues 4-13 of Torchwood Magazine in 2008, and adds at the end a single-episode story, Jetsam, published in issue 3 also in 2008.
I felt that the Rift War! epsiodes did not hang together very well - there was rather a feeling of three different writers (Simon Furman, Paul Grist and Ian Edgington) handing off the storyline between each other without much of a unifying concept. Also I was not attracted by Paul Grist's depictions of the regular characters in six of the ten episodes that he illustrated, though I liked his writing for four of them a bit more. (The artist above is SL Gallant, who I found more to my taste.)
On the other hand, Jetsam was a real gem, written and drawn by Brian Williamson (who has done a lot of Doctor Who art, but this appears to be the only Whoniverse story he has actually written). It's a fairly standard Season 2 alien artefact story, but done with a real sense of warmth and engagement. I hope Williamson can be tempted to do a bt more. Worth getting the book for.