What is an ‘intervening cause’?

An intervening cause comes between one act (or failure to act) which alters the natural and continuous series of events that follows. When an intervening cause is present, since the natural chain of events have been changed due to the subsequent act of another, the initial actor may be relieved of the responsibility for an injury that is produced. In the example provided for proximate cause, the act of the stranger picking up the ball and throwing it through the window is an intervening cause which relieves you from the responsibility for injury which may have occurred as a result of your act. The responsibility for the injury to the lady is shifted and the stranger's act becomes the proximate cause for the lady's injury.