Dhulyn Wolfshead and Parno Lionsmane think they’re escorting the Princess of Arderon to her wedding with the new Tarkin of Menoin, but the Mercenary Brotherhood has a secret mission for them: find out what happened to the two Brothers who were sent on assignment to Menoin a year ago, and who have disappeared.

Once in Menoin they find old friends, the Scholars Gundaron and Mar-eMar. There to investigate some old Caid ruins, Gun and Mar suspect that the disappearance of the Mercenary Brothers is linked to a series of killings. When the Princess of Arderon’s corpse is found, mutilated in the same way as the others, Dhulyn and Parno track the killer into the Path of the Sun, an ancient labyrinth from which people sometimes don’t return.

But Mercenaries are not ordinary people, and Dhulyn and Parno draw on their Schooling to reach the centre of the Path. What they find there is another world, a world in which the Red Horsemen — Dhulyn’s nomad people — have not been wiped out, a world in which the Marked are hunted down and killed as ‘broken’.

Dhulyn and Parno must locate their missing Brothers, identify the killer, and find their way back through the Path of the Sun before Dhulyn’s own Mark is discovered.