Brunel and the Aliens

When a family of aliens escape from their recently-exploded planet in a Bath Stone time machine, they are trying to find Brunel. Brunel has been time-traveling with the now-deceased alien father for years and holds the secrets to interplanetary travel. But how do the aliens get to the right time period? With inadvertent adventures in Roman Britain, the 7th century with St Aldhelm, wartime Britain, the aliens realise that they need to find a time and place that will welcome anyone... even aliens.