Grotius soon afterwards addressed a letter to the States-General denouncing the statement of Muis as a fable, and these persistent attempts to injure him as cowardly and wicked.

A few months later Madame de Groot happened to be in the house of Daatselaer on one of her periodical visits to Gorcum.  Conversation turning on these rumours March of attempts at escape, she asked Madame Daatselaer if she would not be much embarrassed, should Grotius suddenly make his appearance there.

“Oh no,” said the good woman with a laugh; “only let him come.  We will take excellent care of him.”

At another visit one Saturday, 20th March, (1621) Madame de Groot asked her friend why all the bells of Gorcum march were ringing.

“Because to-morrow begins our yearly fair,” replied Dame Daatselaer.

“Well, I suppose that all exiles and outlaws may come to Gorcum on this occasion,” said Madame de Groot.

“Such is the law, they say,” answered her friend.

“And my husband might come too?”

“No doubt,” said Madame Daatselaer with a merry laugh, rejoiced at finding the wife of Grotius able to speak so cheerfully of her husband in his perpetual and hopeless captivity.  “Send him hither.  He shall have, a warm welcome.”

“What a good woman you are!” said Madame de Groot with a sigh as she rose to take leave.  “But you know very well that if he were a bird he could never get out of the castle, so closely, he is caged there.”

Next morning a wild equinoctial storm was howling around the battlements of the castle.  Of a sudden Cornelia, daughter of the de Groots, nine years of age, said to her mother without any reason whatever,

“To-morrow Papa must be off to Gorcum, whatever the weather may be.”

De Groot, as well as his wife, was aghast at the child’s remark, and took it as a direct indication from Heaven.

For while Madame Daatselaer had considered the recent observations of her visitor from Loevestein as idle jests, and perhaps wondered that Madame de Groot could be frivolous and apparently lighthearted on so dismal a topic, there had been really a hidden meaning in her words.

For several weeks past the prisoner had been brooding over a means of escape.  His wife, whose every thought was devoted to him, had often cast her eyes on the great chest or trunk in which the books of Erpenius had been conveyed between Loevestein and Gorcum for the use of the prisoner.  At first the trunk had been carefully opened and its contents examined every time it entered or left the castle.  As nothing had ever been found in it save Hebrew, Greek, and Latin folios, uninviting enough to the Commandant, that warrior had gradually ceased to inspect the chest very closely, and had at last discontinued the practice altogether.