After the near-suicide mission to the Norweigian fjord, which had claimed so many lives, morale among what was left of 633 Squadron is at its lowest ebb. Unbearable tension, stupid wrangling among the survivors and problems with replacement recruits are tearing the squadron apart. Vesuvius – this was the mission on which the success of D-Day depended. The chosen squadron was no.633, and their target was a fjord in Norway, where the Germans were known to be developing something so secret that not even the crews of the Mosquitoes which were to fly on the mission could be told about it. All they do know is that they will be flying in low, between the steep mountain walls, without fighter support. Most of them will be flying one way only…