11.4 Shellshock by Simon Barnard and Paul Morris
When the TARDIS lands behind German lines at the height of the First World War the Doctor finds himself inadvertently transported to a hospital full of traumatised soldiers. They’re suffering from shellshock but also something else. Something causing vivid nightmares that chill the blood. Something not of this place.
Things are not quiet on the Western Front.
Note: This title is also available on CD as part of Doctor Who: The Fourth Doctor Adventures Series 11: The Nine