Q returns to Voyager with ovations towards wooing Captain Janeway in order to mate and produce offspring. Janeway doesn't buy it, but the matter, indeed, is more serious than Q lets on. The death of the other Q (a.k.a. Quinn) in their previous encounter has thrown the Q Continuum off balance. Civil war has broken out, with the struggle adversely affecting the galaxy. Q's side is losing, but a child, to Q's way of thinking, may restore that balance, and mating with Janeway might be an infusion of new blood that the Continuum needs. Then there's the other woman - Q's Q-mate - to consider.
—statmanjeff