The Doctor takes Rose to the year five billion, where they land on a space station orbiting the Earth named Platform One. Among the elite alien guests assembled to watch the Earth be destroyed by the expanding Sun is Lady Cassandra , who takes pride in being the last pure human, though she has received many operations that have altered her image. It is discovered that Cassandra, to receive money for her many operations, plans to let the guests die and then profit from the stock increases of their competitors. She releases discreet robotic spiders all over Platform One, and they start interfering with the systems. She departs via teleportation and the spiders bring down the shields, causing harmful direct solar radiation to penetrate the station. The Doctor manages to reactivate the system and save Rose, after which he brings Cassandra back and she ruptures from the intense solar heat.