Above the peaceful Walthamstow Marshes, a hungry kestrel eyes its prey while two young field mice, Diesel and Electric, play innocently below. Venturing out from their family nest within the railway embankment, the duo finds danger swooping down upon them. As the kestrel descends, allies from the marsh emerge: a vigilant rabbit and brave sparrow leader, Brown Wings, rally to protect the young mice. Diesel and Electric is a tale of unexpected friendships and nature's camaraderie unveiling amidst a thrilling struggle for survival in the heart of the marshland.