I'm a sucker for time travel fiction, although I admit that much of it isn't really all that good.

Travelers is a series about people sent back in time from the post-apocalyptic frozen remnants of civilization to inhabit the bodies of people who were about to die. It's sort of a moral imperative as well as a logistical step as the new owner of the body will need to minimize their non-mission impact on the future.

Travelers is also very good.

Now, it's not time travel in the traditional sense as it's one-time, one-way, and your body doesn't get to go. Rather think of it akin to uploading your consciousness to the cloud (which I always view as a copy, and the death of the original but that's a side discussion) and then downloading it to a new Host. The Rules state that the most recent chronological transfer to a host sets the line for how far back one can go. The first transfer takes place in 2001 and so no one will be sent from the future to any time before then. If a mission fails, a new traveler can overwrite the previous and try again, but this both puts physical stress on the host and effectively kills the previous traveler as they must be deleted to make room for the next attempt. One episode in particular focuses on this, spending the entire allotted time in a life and death race to save the future.

Naturally, there is opposition. After our main characters are sent back, the future results in a 'rebel faction' attempting to prevent the construction and powering of the supercomputer responsible for managing both the time travel program and the remnants of humanity - viewing the electronic overlord as a technological master rather than a tool.

I don't know for sure if the series is over now. It had a soft finale that could work as a series ending, or equally well as simply the end of season 3.

Anyway, that's a brief spoiler-free overview. I recommend it.