Frank Wylie

The Zero Room is gone, and the Doctor’s regeneration is unstable. To help him, Tegan locates the tranquil world of Castrovalva and the TARDIS heads there.

Something is wrong with Castrovalva, but the Portreeve cannot help the Doctor identify the problem. And the Master is taunting Adric, caught in his web of power.

As recursive occlusion threatens to destroy everything and everyone in Castrovalva, the Master’s space/time trap is revealed, with Adric at its heart.