After spending six generations flying through the Riemannian Universe, the crew of the starship “Incomparable” must take a reverse course and arrive in their home system just in time to save their world from destruction: the technologies developed by the society of the ship already allow this, and the paradox of the twins Igana works in the opposite direction. But how will foreknowledge of its outcome affect the great mission? After all, the physics of Riemannian space provides for more than one arrow of time, and it is so tempting to construct a device that allows the “Incomparable” to adjust the flight path in accordance with news from the future...< /p> True, no one guarantees that these news fully correspond to the true course of events. Greg Egan. The Arrows of Time. 2013Translation from English: