This episode was suprisingly a little bit weak than the first one. I really couldn't understand some of it and maybe that's why. But generally it was predictable in a way.
The story goes with the problem starting from the mother's death, leaving two children under the care of their stepfather (?). Then came the death of the male sibling. And it looked like another suicide event using suffocation as a medium aka carbon monoxide poisoning. However as usual, it's not as it seems. An investigation was launched at the request of the real father of the children. Now i'm not sure why stepdad killed the boy but it was implied that the he was lusting after his stepdaughter. It was a good thing that she seemed to have listened to the warnings of Enamoto as she averted one disaster from happening. That coffee was definitely drugged.
So as the drama progressed we see the stepfather performing magic at school. He showed how science is applied to it.And how heat is a factor in expansion or something like that when he was demonstrating how the plunger of the syringe was moving while being heated. I think since Enamoto was there to witness this that he got the pieces of the puzzle together. (And from here on,it got predictable for me.)
Two lawyers and Enamoto go back to the room, they start to investigate by putting back the clues together. Tape was placed on the windows and on the door. The duck tape on the door was a mystery to Enamoto, something to do with how it's positioned at the door. He was also wondered why they could not open the door during that time. Well, it was explained later when they found out that it was tampered with paper wrapped around the lock. The drama explained itself fully on this part.
Now what would have caused the death of the kid? I don't know if the stepdad drugged the food of the kid with a sleeping pill and finished him off or killed the kid even before the set up was made. But for sure the boy was exposed to a chemical or something that caused heat and gas to expand in the room. If the boy wasn't dead before that he would have died from what he was exposed to. The heat generated also explains the mystery about the duck tapes around the door. As an explanation I would refer you to atoms and heat - science 101. Heat causes expansion and since there was no point of exit since all the escape paths were taped off, it would have caused an explosion if unchecked. From what I garnered, the culprit set the airconditioner on a timer to cool the room later thus preventing this from happening.
Obviously these were all circumstantial, the link that pointed to the stepfather was that small piece of paper that contained traces of the chemical and possible prints. Sad part was that the boy who died seemed smart and was studying into getting into a school as evidenced by all the books in his room. Of course, my deductions could be totally off mark.
Now as much as I also enjoyed this episode, the plot was a little bit weaker. The writers should come up with something more original than with people dying in locked rooms all the time. They cannot go on with the concept of 'it looked like suicide, no it's murder. Let Enamoto prove it' plot. I hope they put fresh ideas on the next few episodes. Something that will make the audience crave for more. Well, that's just my opinion anyway.
As always, I made the review based solely on the raw drama and may not be accurate. Again I am not translating just speculating from visual media provided.