In the Parker Pyne short story The Case of the Discontented Soldier, Johnny is the name of a boy employed by Ariadne Oliver to pour water into the cellar of the Whitefriars house through a hole in the ceiling. Major Wilbraham and Freda Clegg had been taken prisoner and bound in the cellar as part of a scenario scripted by Mrs Oliver. The water was to create the impression that they would be drowned. Wilbraham and Freda had earlier paid Parker Pyne to create some excitement in their lives.
Johnny does not appear in the TV adaptation of the story. The water was controlled by Madeleine de Sara and the actor Lorrimar.