Not too bad of an episode, though I felt that such a professional killer being killed so easily was a bit of a crock. When Chin was knocked out and dragged to the basement I really doubt such a careful serial killer would take the time to do what he did and let himself be killed. Obviously we're not going to lose Chin, so we all knew that was the end of the killer.
Also, while the part about the Japanese tsunami victim getting his belonging back was quite moving (especially since I was there when it happened), I'm always a little dubious when this kind of thing or a Japanese actor (or Japan) is put in a TV serial because I know that in many cases it is to increase viewership overseas. In this particular case, though. Shows from the US that feature Japanese actors often come to Japan almost immediately after aired in the US, but if not take one to three years for a season to air. Flash Forward came here soon after season one because it had a Japanese actress and featured scenes in Japan, and people are talking about Helix already because it has Sonada (an excellent actor, BTW). I'm all for diversity in a TV crew, and am very happy to see more and more Asians making it to 'the big leagues', but there is often underlying politics and money at play. It works a LITTLE better with Hawaii Five-0 because there has always been a strong connection between Hawaii and Japan, there IS actually tsunami wreckage washing up on Hawaiian and North American shores and stories of things being returned, and a lot of people of Japanese descent in Hawaii (and they worked in the 'Christmas gift' and giving angle), so I think it worked to an extent. Still more or less a side-story within the episode.