Perhaps Louis would have gone further still, perhaps he was plotting even now the immediate destruction of Flanders. Towards the close of the year 1320 when Robert, after signing at Paris the treaty in question, once more returned to his native land, thinking to obtain some little breathing time before he set out on the last dread journey, his chamberlain introduced to his presence a young man, who, in a voice broken with tears, avowed that he had been commissioned to poison him. 'And wherefore didst thou think to commit this crime?' said the old Count. 'Sir,' replied the youth, 'I was driven to it by the Prince of Nevers, who bade me follow the instructions of Brother Walter the hermit'--a monk whom Robert loved well--and little by little he learned that his death was to have been the signal for an outbreak which was to hand over all Flanders to the King of France. Whatever may have been the truth of the mysterious youth's story; Robert believed it, presently Prince Louis was arrested and thrust into prison, and it was probably owing to the intervention of the burghers, who either did not credit the charge against him, or were still influenced by feelings of regard for their old champion, that his life was spared. Be this as it may, the Count of Nevers was shortly afterwards set at liberty on his undertaking to leave Flanders within eight days. This was on the 6th of April. No sooner was Louis a free man than he set out for the French capital, where, three months later, on July 6, 1322, his inglorious career came to an end, and only two months afterwards Count Robert himself paid the debt of nature. Rumour said that both Robert and Louis had been poisoned by Robert of Cassel--a younger son of Robert of Bethune--and that he had driven his elder brother out of Flanders with a view to his own succession. Certain it is that the Lord of Cassel at once set claim to the throne, and at first it seemed probable that he would obtain it. He had for a long time past been mustering his forces, and now he had at his disposal a considerable army; all the stronghold in Flanders were in his hands, his father's ministers were his staunch and devoted friends, and so redoubtable did he seem that the French King refused to accept the homage of Louis of Nevers' eldest son, who also claimed the throne, and was now in Paris, alleging that it was for the Court of Peers to decide who was the rightful heir to the county of Flanders.