Description: Two observers - one man, one woman - stand on a flat observation tower: they suddenly rush below. Close-up of the two (woman with binoculars, man with earphones). Various shots of this, from behind and side. The two 'trace' flying bomb on an elaborate charting device, then lift a hatch, and press a button: the man shouts through a microphone; the girl swivels the plotting table, and looks through sight; on the table are marks at various points of the compass ("No 2 Group, Horsham Centre" etc); various shots of the plotting sight being adjusted; film of the results of the button being pressed: a small rocket ignites outside the observation post, giving a flare-trail. Near the hut, a stack of tubes (rockets?) and a truck. General pan around the countryside.