Deeply frustrating. Great acting, great characterisation, challenging plausible scenarios all ruined by a drama with the pace of a moribund sedated snail. With a bit of imagination with timelines we could have merged a dramatic present with the back story, instead we have back story of back story on a dreary present. Has potential to be really good. I can see what they are trying to do is to explore humanity and consequences of decisions made in pursuit of knowledge and experience. Very worthy and potentially wonderful. Well worth watching but more like educational television than drama or Science Fiction.