31601 & 50008 Thunderer pass Castor on 11 April 2015 with the 2M42 09:30 Peterborough to Wansford service, during the Nene Valley Railway's Diesel Gala. It had just stopped raining, but as the sun was yet to appear, I initially wasn't going to bother with this shot. However, a 31 and 50 combination on foreign rolling stock has a certainly novelty value!