McFall made her literary debut with Blackfin Sky (2013), a haunting mystery about a girl who returns to her hometown after everyone believes she has died. Her breakthrough came with Ferryman (2013), which follows Dylan, a teenager who, after dying in a train crash, must cross a perilous wasteland guided by Tristan, the ferryman of souls. The novel became a publishing phenomenon in China under the title 《摆渡人》, selling millions of copies and topping bestseller lists for years. It was followed by the sequels Wayfarer (2017) and Borderland, completing the Ferryman Trilogy.
Her other notable works include Bombmakers (2015), a tense thriller about teenage bomb-makers, and Outwalkers (2018), a dystopian adventure set in a divided future Britain. McFall's vivid storytelling and heartfelt themes of love, sacrifice, and self-discovery have earned her a devoted readership around the world.