Riveting, twisted, and if not original in concept certainly original in presentation (at least for TV). Every piece of the puzzle is put in its place with mathematical precision (and no, it's not that confusing - if you have a functioning brain, that is!). The visuals and sounds of going back in time are somehow spine-tingling - after a while, you begin to wait for them. It really is a brilliant concept: instead of the usual cause-and-effect viewing order, here you first see the effect and later the cause. The only flaw is that you'll probably be able to guess the killer at the end of the 4th episode. But even if you do, there are still more things to be revealed. Very well acted by all - Jodi Balfour is superb and a revelation. Highly recommended, if you like serial killer thrillers and don't mind exploring new ways to tell a story. *** out of 4.