The GN&CR was bought in 1913 by the Metropolitan Railway (MR), which operated what are today the Metropolitan and Hammersmith & City lines and the former East London line. The MR had plans to link it to the Circle and Waterloo & City lines, but these were never fulfilled. During this period, the line remained an isolated branch, without through services to any other part of the rail network. Carriages were brought to it through a connection into a freight yard near Drayton Park station, where a small depot was built to service trains.