The survivors of a devastated future Earth lie in suspended animation on a great satellite. When Earth is safe again, they will awaken. But when the Doctor, Sarah & Harry arrive on the Terra Nova, they find the systems have failed & the humans never woke. The Wirrrn Queen has infiltrated the satellite, & laid her eggs inside one of the sleepers. As the first of the humans wake, they face an attack by the emerging Wirrrn. But not everyone is what they seem, & the only way the Doctor can discover the truth is by joining with the dead mind of the Wirrrn Queen. The price of failure is the Doctor's death, & the end of humanity. This novel is based on a Doctor Who story which was originally broadcast from 25 January to 15 February 1975.