Janeway was killed off in TNG: Before Dishonor (which is a book you either hate or love, there are no in-between options), absorbed by a living Borg cube, then she temporarily became a pseudo-Borg-Queen (or something along those lines) until they destroyed the Borg cube (after it ate Pluto, just roll with it). She later returned in VGR: The Eternal Tide which is a lot better than Before Dishonor.
I like Before Dishonour and have read it a few times over the decade since it was published, as for Eternal Tide, I read it once and personally think it is the weakest of the Voyager novels under Ms Beyer.