In this latest in the popular S-Squad series the team are sent into a remote area of the Libyan desert to rescue a team of researchers who have gone missing. When their search leads them to a lost city in a high desert canyon they find that they are also following in the footsteps of a previous Scottish squad, a team from the Victorian era. The city is overrun with an infestation and soon the squad are separated and under siege. Can they avoid the fate that befell their predecessors and find their way to safety?