Release Message:  While the Doctor plans a holiday to Metebelis Three, Jo (Katy Manning) and the Brigadier are intrigued by a mysterious death at a coal mine in Llanfairfach.

Description:  While the Doctor plans a holiday to Metebelis Three, Jo and the Brigadier are intrigued by a mysterious death at a coal mine in Llanfairfach, which is being blamed on local company Global Chemicals.