Continuum, Season 4
After three seasons considering all the implications and duplications created by travel across timelines, in this season we see a device that brings soldiers from the future of the same timeline (the one we are following with the characters). These soldiers are meant to build an even more powerful device for a mass scale migration that turns out to be an invasion rather than a life-saving mission from a future about to collapse.
All time-travel in this season is within the same timeline, so instead of creating new ones, or travelling from one to the other, we see a the "rewriting" version of time-travel. Just as in Fringe, the creation of new timelines and the rewriting of timelines coexist as consequences of time-travel, which makes this show very interesting.
SPOILERS ALERT: Kellog's is sent to prehistoric times with this device, and therefore the future of the timeline is rewritten into one without him and his army in the future. Therefore the invasion is avoided. Through this device, Kiera manages to get back to the future, but it's obviously not her own (as everyone kept telling her during the entire show) but the future of this timeline. There she sees the Kiera of this timeline, which after the rewriting never left 2077. But "our" Kiera killed the Kiera of this timeline in Season 3 - so despite the great care the filmmakers showed to conserve consistency, here we stumble upon the pervasive paradox, namely that two realities coexist at the same time: Kiera killed her alter ego and at the same time she didn't. Which one does she remember? This presents us again withthe reality that it is impossible to consistently write a show on time-travel without reaching a paradox...