Five women become unlikely friends when they all stay in the same British public hospital. As they get to know each other, they discover that their lives intertwine—through bosses, ex-husbands and lovers. And the death of one of them, apparently from complications from surgery, seems to bring the others even closer. But when another is brutally attacked, the three remaining friends realize these deaths are connected and they must uncover a dangerous, psychotic killer who may be within their very circle.