The Fourth Plane at the Flypast

They are common enough, World War II commemorative flypasts, although dwindling in numbers as the venerable Lancasters and Spitfires gradually give up their ghosts. Sue and John are watching such an air display, when they, and only they it seems, notice an extra plane in the sky: The Wellington, with the black fuselage and the hole in the side, and one engine not working. They couldn't have been mistaken. Or could they? There was no sign of it landing anywhere. Spooky! The apparition won't go away. Why is it happening? Is it hallucinations? Well-constructed plot keeps the suspense as Sue and John get personally involved in the mission of the mysterious Wellington.