Conduct amounting to a breach of duty often causes loss to the person to whom the duty is owed. But sometimes the duty-holder in breach, being insolvent, is a man of straw not worth suit. Other times, the prospect of suit is unattractive given the possibility of jeopardising existing relations with the duty-holder. To seek an adequate remedy, one is then tempted to expand one's search to the surrounding circumstances leading up to the breach. So we peer up the chain of events. We search for persons—accessories—whose conduct contributed to the objectionable outcome. But the further up you go, the more diluted the contribution. And that presents a problem.