Horror/Thriller. Liv Tyler, Scott Speedman, Gemma Ward, Kip Weeks, Laura Margolis, Glenn Howerton. Director: Bryan Bertino.

ATTACK is often the best form of defence, but what happens when you are faced with protecting the people you love from a faceless adversary who has no scruples or motive?

How do you fight back against someone, unmoved by emotion, whose aim is to inflict the most unimaginable pain? The Strangers imagines the battle of wits between a young couple and three masked intruders who invade their home at night.

For the first hour, writer-director Bryan Bertino's debut feature is an edge-of-seat thriller, cranking up the suspense until our knuckles are white. We watch with mounting dread as the couple creep around the house, eyes wide and breathing laboured, unaware that the tormentors are hovering in the shadows.

Ambient sound effects such as a creaking floorboard or the distant barking of a dog heighten our unease. A deafening knock at the door breaks the agonising silence as the nightmarish game of cat and mouse reaches its brutal climax, with the couple pleading for their lives.

"Why are you doing this to us?" whimpers the female victim.

"Because you were home," one of her attackers replies coldly.

The Strangers opens with Kristen McKay (Tyler) and her boyfriend James Hoyt (Speedman) fleeing a friend's wedding reception early.

Rose petals strewn throughout each room of their brick ranch house and an engagement ring burning a hole in James' pocket confirm our worst fears.

"Things didn't work out the way I'd planned," whispers James in a voicemail for his best friend, Mike (Howerton), "I'm going to need you to come out here to get me."

The couple sit awkwardly, until there is a knock at the door.

"Is Tamara here?" asks a young woman, who subsequently disappears into the night, perhaps to visit a neighbouring house.

While Kristen runs a bath to unwind, James drives to the local store to pick up cigarettes.

Meanwhile, three figures - Dollface (Ward), The Man In The Mask (Weeks) and Pin-Up Girl (Margolis) - prepare to break in.

The Strangers is an impressive first effort from Bertino, demonstrating considerable restraint in terms of the lean script and direction. Dialogue and incidental music are used sparingly, relying on emotionally wrought performances from the two leads.

Tension dissipates once best friend Mike arrives and the film's logic buckles noticeably to ensure Kristen ends up back in the house, at the mercy of the deadly trio for the gratuitously violent finale, rather than running to get help.

The identities of the attackers are never revealed, enacting their despicable plan almost without exchanging a single word, except for a chilling final remark: "It'll be easier next time."