Travelers are people from the future that transfer their consciousness to people from present time (who are ready to die, because the show doesn't want as feel bad). For some reason the families, friends and husbands/wives doesn't seem to notice or care much for the new difference in personalities. But here comes the real stupidity: The travelers act like the previous life of the host is important to them. Why? Why? Why? The explanation is that they try not to interfere with the past, but the people whom lives occupy were supposed to die. It isn't like travelers lack money or supplies. The reason is that this shows want's to insist on exploring emotional relations that are not based in any logic. The show is lazy and tries to sell cheap emotions. There are other major plot holes, i know that this is to be expected in a time travel show, but oh my god there so dumb.
This is not a spoiler, i am talking generally.
This is not a spoiler, i am talking generally.