I think this is one of the best books written by that author. The main character Clio, is a Time Dive pilot (one that is capable of guiding a ship into a "time stream"), who with two other colleagues are making a forbidden time dive to the future - and stayed there long enough to record a dying Earth's final transmission. Returning from the other Earth like planet (planet Niang with a colossal forest and vast rivers) with a small payload, she is trying to plant those "seeds of life" back on Earth - so that they could stop Earth's demise (since the ozone layer is pretty much depleted, the planet is dying as the ultraviolet irradiation is killing off all the plants).
The book also presents an interesting view on:
One: "Alternative Realities"/"Alternative Worlds" - as these parallel worlds are unable to survive indefinitely in one universe, one dominant "reality" will eventually always triumph over the other. I won't say anything more here (as not to spoil the main story line), but I've found this concept quite thought-provoking/intriguing in itself.
Two: Time-traveling space ships - where by traveling back in time, the ships arrive at point when parts of the galaxy are passing through the same space as our solar system currently occupies (you could say the that galaxy rotates independently "under" the ship, and upon re-entering the "time stream" the Dive ship will have jumped a large distance of space). This allows the ships to overcome impossibly vast distances from Earth to other star systems without using FTL technology.
It is a pure and great sci-fi action adventure with very interesting and greatly developed main characters: obviously Clio Finn but also Harper Teeg and Peter Zee. The story of course, is not that simple as the one outlined above (the plot has many twists and turns along the way), but it is a very satisfying read. For fans of science fiction and time travel this is a must read.