Enterprise is due to rendezvous with Degra but ends up somewhere in a place and time where nothing seems right.
Much of the plot has been taken from previous Trek incarnations but it does work for the purpose of this episode. It starts off with an excellent and highly intriguing premise and the events unfold in a compelling and sometimes ironic way. I was thoroughly enjoying up to a point where the main guest character gets into some big expository dialogue to explain his behaviour and from then on my interest began to wane.
The concept of the guest characters was mostly good as it allowed the series regulars an interesting glimpse into a possible future. I found all this to be plausible and bought into it for most of the characters. One didn't work for me, mainly due to the dodgy makeup effects and the focus on an ongoing sub-plot and love story that has never interested me throughout the duration of the show.
When reading the reviews of others, I noticed one making a good point about time-travel being overused in sci-fi. It's a difficult one because some of the best plots involve time-travel, but the more of them you see, the more it diminishes their impact.
E² has a pretty exciting finish which did pique my attention once more towards the end. Once the reset button is eventually pushed you do suspect the overarching plot just took a detour for the sake of achieving the full number of episodes required for a series as it nears the conclusion.
I think overall it was good, but given the premise I wish it had been better. Much of this down my own personal interest in certain characters.