It is not clear what happens to the Rocket Group immediately after this: the next time Quatermass is seen on screen ("Quatermass", also released internationally as "The Quatermass Conclusion" and "Quatermass IV", 1979) he has long been retired, living in retreat in the Scottish Highlands. He has recently become the guardian of his teenaged granddaughter Hettie after her parents were killed in a road accident in Germany. After Hettie runs away from home, he travels to London in search of her and finds a dystopian world there. Quatermass and the scientist Joe Kapp establish that an alien probe is causing the collapse of society by feeding on the world's youth, and Quatermass forms a plan to drive the intruder away by the detonation of a nuclear bomb. He presses the button to detonate it himself, with Hettie's help, and they are killed in the blast as the planet is saved.