Engineering work is taking place between Watford Junction and Euston on August 8 and 9, closing the Lioness Line. An overground train (Image: Alamy/PA)A National Rail spokesperson said: "Engineering work is taking place between Shepherds Bush and Watford Junction, closing lines an various points over the weekend. "From approximately 20:00 on Saturday evening until 12:00 on Sunday, and from approximately 21:00 on Sunday evening until the end of service, no Southern trains will run between Shepherds Bush and Watford Junction. "You can use alternative London Overground trains between Clapham Junction and Willesden Junction at no extra cost." Tickets will be accepted on London Northwestern Railway services between Euston and Watford Junction.