I'm not really sure what I can say about this one at all. For a start it's the beginning of a kind of mini-arc, ending at Seeing I, in which the Doctor and Sam get seperated (quite early on in this book), and in which some of the same players play a part throughout. But despite that it's more like a little bit of shared-universe-space than a mini-series.
Anyway, it's a fairly standard kind of story; some humans have been messing around with time-travel devices that they don't understand when a whole set of aliens turn up to reclaim them. The Doctor of course rants and rails about how they shouldn't mess with things they don't understand, but….
There's nothing I can point at and say "I don't like this" about this book, but it's got nothing going for it either.