Rupert Evans stars as David, a film archivist who starts to suspect that his beautiful wife (Hannah Hoekstra), and mother of his child, is cheating on him. Things culminate in a night full of dark imagery and David passing out, only for him to awake the next day and eventually discover that his wife has not returned home. He believes that something very bad has happened to her, something caused by an entity that may also be after his young son (Calum Heath). But the main police officer (Steve Oram) who ends up investigating the disappearance keeps David in his sights as the main suspect, especially as his behaviour starts to deteriorate.
Kavanagh takes a number of familiar genre elements here and blends them together into a masterful display of what modern horror can do to creep out viewers. Almost every scene is an audio and visual selection of unnerving details, with the grand finale an all-out barrage to the senses that may well make even the hardiest horror fan experience a goosebump or two. And the very last scene is . . . . . . . . . . . . well, it was as inevitable and yet shocking as the final scene in Kill List, for my money.
Evans is fantastic in the lead role, a performance that sees him going through the wringer for almost 90% of the runtime. He's always sympathetic, even as his sanity is called into question, and it's hard not to keep hoping that there's some light at the end of the tunnel for him. Heath is a very sweet young lad, and does well to keep running along with his father as things start to get scarier and scarier. Kelly Byrne is likable enough, playing a young nanny who tries to help for as long as she can, and Antonia Campbell-Hughes isn't bad, despite her speaking so breathlessly at times that I thought she was about to expire mid-sentence. Oram puts in yet another great turn, he's certainly been racking them up in recent years, and Hoekstra does alright, although she's not onscreen for all that long, obviously.
The main problems I had with the film stem from the editing/structure that removed the element of surprise on a number of occasions. Oh, there are a couple of cracking moments that could well make your jaw drop, but it's a shame that there couldn't have been more of those. It is, however, understandable that Kavanagh decided to forgo more shocks and surprises in favour of genuine tension and scares, and I have to end up, paradoxically, also giving him credit for not trying to be too clever in a way that would have undermined the third act.
All in all, this is absolutely the kind of film that horror fans should seek out, support, and hope to see more of. Like the titular waterway, it's dark, it's chilling, and it's got depth.
And/or you could also buy my e-book, that has almost every review I've written over the past 5 years. It's very reasonably priced for the sheer amount of content.
The UK version can be bought here - http://www.amazon.co.uk/TJs-Ramshackle-Movie-Guide-Reviews-ebook/dp/B00J9PLT6Q/ref=sr_1_3?s=digital-text&ie=UTF8&qid=1395945647&sr=1-3&keywords=movie+guide
And American folks can buy it here - http://www.amazon.com/TJs-Ramshackle-Movie-Guide-Reviews-ebook/dp/B00J9PLT6Q/ref=sr_1_fkmr0_1?ie=UTF8&qid=1395945752&sr=8-1-fkmr0&keywords=TJs+ramshackle+mov
As much as I love the rest of the world, I can't keep up with all of the different links in different territories, but trust me when I say that it should be there on your local Amazon.