The Edge Of Destruction - Gang Wars

It's a two part story set entirely inside the TARDIS but what is this story actually about?

Sarah describes the gang wars taking place between the regular characters and the TARDIS beds. Mark discusses his experience of meeting William Russell. 

If you're new to Who and want to discover these stories with us, we watched this from the official BBC DVD box set 'The Beginning' but this story is also available to stream online via Britbox.