The Oxford to Bicester line is mainly operated by DMUs, so the HST diversions over the route on 17 September 2017 were definitely worth photographing. Two for the price of one here, as 43025 The Institution of Railway Operators brings up the rear of the 1A22 11:01 Penzance to Paddington GWR service at Charlton-on-Otmoor, while in the distance 43088 approaches with the 1C21 15:32 Paddington to Penzance.