The ancient forest realm of Sunweald is bordered on two sides by far mightier nations – a precarious situation. At its centre, the Sunweald Palace is home to the Lord Regent and the heir to the throne, together with numerous precious and powerful artefacts. The Palace is protected by the realm's elite Shields, dedicated to guarding the royal line against all foes.
A group of vicious brigands called the Wildwood Reivers have been stealing arcane artefacts and smuggling them across the borders, out of Sunweald. And the objects they most desire are stored in the mystical Wyrm Vault, hidden away deep in the bones of the earth, within the walls of the Palace itself. As political and religious tensions mount, Sunweald's druids prepare to enact rituals for the Summer Solstice – but the Wildwood Reivers and their treacherous allies have other plans. It falls to Briar, the commander of the Shields, to defend the ancient corridors and secret tunnels of the Palace. The odds may be against her, but she'll see every enemy head adorning a spike or she'll die trying…