Prepare for my longest review so far... Wow. Going by the ratings alone, this episode is the absolute favourite of this forum as a whole. It's deserved. It's a high quality, emotional episode that packs a hell of a punch. Unfortunately, some people have decided to rank this below excellent... I'm ashamed to say I was one of them.
Back when I first created this account, I did do a handful of ratings here and there. For the most part my opinion hasn't changed. But with this one it has. I cannot fathom why my 18 year old self would only class this as a good episode. I can somewhat understand my reasoning for not putting it in my personal top 10, but there's no denying this is an excellent episode. I still stand by the fact that this episode is far from perfect, though, and one of the reasons why it wouldn't quite make my top 10 today. And that's for how Sam behaves in this episode.
I can understand the reasoning for not interfering in such a momentous decision, but I can't understand Sam himself (knowing the character like I do) behaving this way. He just comes across as a big hypocrite. In the very next episode he's doing everything he can to change history, even if that only meant given his dad a few extra years of life. I believe Sam cares for Al like a brother, and I don't believe he would have acted so cold like he does towards the end of this episode. For the most part he comes across as indifferent upon finding out (except for a second or two when we see the pain on Scott's face). Even in previous episodes he's thrown the rules aside, like with Donna and then arguably with Nicole. So yes, I do think Sam's behaviour in this episode is a major problem. It just makes him look selfish.
Dean Stockwell elevates this episode into my top 20. His performance alone is what does it. The agony you can just feel in that last scene is heartbreaking. It's just so...gutting. It's pain and that's all it is. There's no bittersweet feeling at all, it's just pure pain and Dean does such a great job with it. Susan Diol doesn't get enough credit either. Her performance as Beth is really good throughout.
The fact that this particular mistake in time eventually gets rectified is what really saves Mirror Image for me. It brings the whole series full circle. But more on that when the time comes for my final review.
My rating. Excellent. A brilliant, heartbreaking finale to season 2.