She had desired to cause trouble for him in his own family, so that he might have no time to oppose the marriage of her son with the queen; but she had shot beyond her mark, and Charles, started thus on the terrible path of crime, had now broken through the bonds of his holiest affections, and gave himself up to his bad passions with feverish ardour and a savage desire for revenge.

Then Catherine had recourse to gentleness and submission.

She gave her son to understand that there was only one way of obtaining the queen's hand, and that was by flattering the ambition of Charles and in some sort submitting himself to his patronage.

Robert of Tarentum understood this, and ceased making court to Joan, who received his devotion with cool kindness, and attached himself closely to Charles, paying him much the same sort of respect and deference that he himself had affected for Andre, when the thought was first in his mind of causing his ruin.

But the Duke of Durazzo was by no means deceived as to the devoted friendship shown towards him by the heir of the house of Tarentum, and pretending to be deeply touched by the unexpected change of feeling, he all the time kept a strict guard on Robert's actions.
An event outside all human foresight occurred to upset the calculations of the two cousins.