 Instead, the brick roof-support arches between platforms 4 and 5 were redressed by the film crew and used to represent a brick wall that does not exist between the real platforms 9 and 10.Within King's Cross, a cast-iron "Platform " plaque was erected in 1999, initially in a passageway connecting the main station to the platform 9–11 annexe.Part of a luggage trolley was installed below the sign