The Sandhurst Road School bombing mentioned in this episode was a real event that took place on the 20th of January in 1943, just after noon. It is considered the worst of the school bombings during World War II. Thirty-two children died during the raid and six more children died while in hospital. Six staff members died as well which includes Mary Frances Jukes, the teacher also mentioned in this episode. A total of sixty others were injured.
This episode is dedicated to director Jeremy Silberston who co-developed the series and has directed several episodes.
The closing credits begin with the phrase 'In Memory of Jeremy Silberston'. Silbertson had directed eight episodes of Foyle's War (2002), the last being Bad Blood (2006). He died of a brain tumour after seven months of illness in 2006 aged 55.
Contains actual film footage of a test of the bouncing bomb.
The bomb development is inspired by the real-life events depicted in the largely fictionalized docudrama The Dam Busters (1955). While partially explained in this story, the bomb was designed to skip over the water until it came in contact with the dam, then sink to the bottom and then explode. It is mentioned that the bombers had to fly at a very low level. This was done at night, with the altitude being monitored by observing a pair of spot lights mounted on the nose and tail of the planes. When flying at the correct altitude, the two lights would line up at a predetermined point of intersection. It is stated that the bombing of these dams would have an enormous impact on the war. It did put some factories out of commission for a month or so and kill many workers and civilians, but in the end, the result of the raids was of limited consequence.