 As a ruse Grimstone pretended he was a staunch Catholic and were supporters of William Stanley the English turncoat.They secretly left the camp provided with letters from the two Spaniards to the Duke of Parma informing that everything was prepared for the admittance of the besiegers into the fort.On 6 October they soon met with Parma and were in conference - Parma obliged them to take an oath on the Sacrament that they were acting in good faith.