Overall, I liked this episode even though there are numerous errors concerning the time travel aspect. One that really has me is concerning Capt. Christopher and how they handle him at the end of the episode. The next paragraph contain spoilers, so readers beware if you haven't seen this episode yet.
When they are ready to beam Capt. Christopher back into his jet near the end of the episode in order to prevent changing the future, how could they beam him back into the jet when he should have already been there piloting the jet? Remember, he was beamed out just before the jet broke up due to the tractor beam. Therefore, if they beamed him into the jet after they beamed him up, the jet would no longer exist.
Overall, not a bad episode. However, I like The Voyage Home better.
When they are ready to beam Capt. Christopher back into his jet near the end of the episode in order to prevent changing the future, how could they beam him back into the jet when he should have already been there piloting the jet? Remember, he was beamed out just before the jet broke up due to the tractor beam. Therefore, if they beamed him into the jet after they beamed him up, the jet would no longer exist.
Overall, not a bad episode. However, I like The Voyage Home better.