The scenario is as follows: Mohammad Amir is bowling with more skill and more confidence than any teenage cricketer is entitled to have. His third ball of the morning has snaked viciously away from Alastair Cook's bat at the last minute to have the England opener caught behind, and Kevin Pietersen is fresh to the crease.
Pietersen watches Mohammad Asif send down a maiden to Jonathan Trott, before Amir begins his first full over of the morning. He takes guard and the typically hushed packed house at Lord's somehow goes even quieter for a second or two.
Amir plays a joker, sending down a delivery that is neither particularly straight, nor does a huge amount in the air or of the wicket.
It is out there - 18 inches outside off-stump, half-volley length - fairly glistening with temptation. But, with thick cloud cover, the ball still new and England 39-2, Pietersen must show the self-restraint of a monk, not the wilful abandon of Don Juan.