I thought the story was really good, it unfolds and unwraps itself, twists in a few different directions and while some bits are relatively predictable, some are less so - so there's plenty to keep the viewer engaged and puzzling over the real story as it unfolds. Ultimately the story proves to be quite deep and well thought out, there's a LOT going on and it spans quite a long period of time.

Visual effects are quite interesting as Lee Ahn uses his ability and they fade the screen between the various memories he's seeing.

Acting - I wasn't totally convinced by Lee Ahn's character, though it wasn't bad at all, just something felt a bit weak in the performance. I thought Jae In was great, and she had some fantastic moments. Sung Mo was brilliant, I found it hard to read him and that gave me some clues as to where his character was heading but even then it wasn't quite 100% - very nicely done.

The little side thing that goes on between Dae Bong and So-Hyun didn't get enough time for me, I thought that was interesting and they only dipped into it occasionally and briefly. It was a good opportunity to expand more on Lee Ahn's best friend and actually put some of the story of him winning So-Hyun over in. It would have added some light moments in between what is otherwise a pretty heavy story. That said, what was in there was good.

Overall I really enjoyed the story, thought the actors did generally a great job and definitely glad to have watched it. The nature of it being a mystery however does make it less interesting to watch a second time as all the mystery is now gone though a second viewing would be interesting to see what clues I missed in the first viewing perhaps.

There's some good surprises and twists in this one - don't let the fact that there are some potential twists that are much more obvious trick you into thinking this one is easily predictable. Definitely worth a watch.