Ex Machina is a continuation of the life threatening problems that still face Susan Milton and David Braun, brought together after the theft of an ancient relic. The Marker has mystical powers, not least of which are great strength and a life extended far beyond the span of mere mortals. Susan, David and the Professor have a plan to get it back, but before they can put it into effect, they make the mistake of recruiting Jo Hallett to help them. As well as a ferocious intellect, she's self-absorbed, unreliable and a disruption to any team she joins - not to mention a gift to its enemies. But she also holds the key to a mystery that's defeated a hundred generations of fanatics: what power lies behind the Marker and the remarkable talents of those who covet it? If she can avoid betraying her friends and being caught or killed by their enemies the answer can be hers - in exchange for her life. In Ex Machina, Jo tells her story.