The document provides instructions for navigating the London Underground when certain lines are closed for maintenance. It explains how to get from Westminster to Green Park by taking the District Line from Westminster to Victoria and then the Victoria Line from Victoria to Green Park. Similarly, it explains how to get from Green Park to South Kensington by taking the Victoria Line from Green Park to Victoria and then the District Line from Victoria to South Kensington. Finally, it addresses how to get from Bank to Liverpool Street using the Underground, as the direct route on the Circle Line may be closed.