This drama could be split into four cases: Gyeonggi Nambu murders, 1995 Larceny case, 1997 Hongwong-dong murders and the final, most important case - Injoo (poor Sun Woo - my heart broke for him.) It actually kickstarts with the kidnapping of a young girl, and the thriller starts. In the first two cases, they did a slow reveal of who the killer was, which was pointless in my POV, because I figured out who was the killer and burglar respectively, in like, 2 seconds. In the first one, the second the bus driver said, "No-one got on at that stop" it was bloody obvious who it could be (hint: it's not the bus driver.) In the second one, there was no witnesses except the rich boy...and lo be'hold - it doesn't take a genius to figure out who it could be. I felt like my intelligence was being mildly insulted, but the walkie-talkie side-drama, kept my score around 7/10. You know - that awesome thing that can communicate with Lee Jae Han in the past :) In the last two cases, they revealed who the culprits were straightaway, so I just settled in to watching the net closing in on them! It was actually kinda fun. My fav bits were the flashbacks on how the crimes were committed, and the human emotion it wrought. We really were spoiled! Also any scene with Lee Jae Han in it. The time looping was very impressive. Questions that I still want to know the answers too: 1) Park Hae Young's phone kept ringing at 11:22, just before the 11:23 transmissions, 2 or 3 times. Who was it? Why was it never mentioned again? (That bugged me the most, surprisingly) 2) Does this have a second season? :) Extra mention to Cha Soo Hyun, she was brilliantly acted by Kim Hye Soo. That woman! Also strangely - my most favourite character besides, LJH, was Ahn Chi Soo. He wasn't quite a good guy, nor was he a full out blown bad guy (I love how he supported the Cold case team sometimes, at odds with his jerkface boss, Kim Bum Joo) and the reveal with his character in ep 11 (was it 11?) was my fav cliffhanger of the show. I like people who straddle both light and dark, in the murky grey area. The soundtrack was great. Really elevated the show throughout. I didn't even realise the last episode was 1 hour and 1/2, I was so amazed that a show, could still remain exciting to the end, raising questions, instead of solving them! Kudos Signal team. You outdid yourselves!