Set in the future on a war-ravaged Earth, four soldiers man Sentinel – a remote military base in a vast ocean that separates two warring continents. They await the relief or the enemy, whichever comes first. But as the empty weeks turn to months, a paranoia descends testing relationships to breaking point. Whilst their tour of duty ended 3 months ago, the relief crew still hasn’t shown up. Alone and uncertain as to their fate, the simmering tension amongst the crew only escalates when a mysterious boat drifts into range – is it the help they have been waiting so long for, or something far more sinister?