Yes rather disappointing. It started out in the same vein as Broadchurch but turned out nowhere near as good. So many red herrings or irrelevant sub-plot and details: the bleeding fingernails, Steve's uneasiness and near-breakdown, Tom trying to claim his mother's pension, the car crash, the padlocked door (wouldn't most rooms have a key with a lock anyway?), Tom lying about his past, wossername giving an injection (possibly) to her stepson .... and it was Tom all along, apparently just because he was some sort of deranged psychopath, so nothing he had done made sense even with hindsight..