The End of the World

Location: Platform 1 (A space station orbiting Earth)
Date: 5,000,000,000 AD
Enemy: The Lady Cassandra
The Doctor takes Rose on her first voyage through time: to the year five billion, when the Sun is about to expand and swallow the Earth. She is cautious and soon starts to question her reasons for joining The Doctor. But amongst the powerful alien races gathering to watch on Platform One, a murderer is at work. Who is controlling the mysterious and deadly metal spiders?