As he waited there, a captive lady, closely guarded, was brought out from the fortress into the courtyard, where she was informed by Lord Walton that she was about to be escorted to the Parliamentary tribunal, there to receive her sentence.
The despairing looks of the captive lady moved Arthur to deep pity; and on learning from Lord George that she had been imprisoned several months in the fortress as one strongly suspected of favouring the Stuart cause and of having acted as their spy, and that she would certainly be condemned to the scaffold, the young Cavalier, as a fellow-adherent of the Royalists, determined to seek speech with her.
Therefore, whilst the attention of the officers and guards was turned in another direction for a short time, he managed to get sufficiently near the lady to enter into a low-toned conversation with her; and then, to his utter horror and dismay, he discovered that the captive was none other than the widow of the unfortunate Charles the First, Queen Henrietta, who, whilst engaged in disguise on a secret enterprise on behalf of her fugitive son, had been captured by her enemies and thrust by them into Plymouth fortress, where, though still preserving her incognito, she knew herself to be in the utmost danger.
Arthur, ever faithful to the Stuart cause, now felt it to be his sacred duty to rescue the unfortunate Queen from her desperate situation; and he told the unhappy Henrietta that he would do all in his power to save her.
At this moment, the bride and her maidens returned to the courtyard; and Elvira, whose tender heart could not bear that another should be in trouble when she herself was so full of joy, at once approached the captive lady, for whose sad fate she had many times grieved, and tried to cheer her with words of comfort. She even playfully removed her long bridal veil, and drooped it over Henrietta's dark locks, clapping her hands merrily at the effect, and declaring she would make a beautiful bride; and the Queen, forgetting her sadness for the moment, was so charmed with the youthful grace and sweet innocence of Elvira, that she indulgently suffered her artless playfulness.
The time for the ceremony was now almost due; and Elvira was hurried away by her uncle to the chapel so quickly that she had not time to don her veil again, but gaily called to Henrietta to follow her with it, forgetting in her eager excitement that the poor lady was a captive.
As the bridal party trooped into the chapel, Arthur slipped back to the courtyard, blessing the happy chance which had left Henrietta in possession of the bridal veil; and bidding the Queen to wrap it closely about her face and form, he hurried her to the gates of the courtyard, hoping that she might now be mistaken for Elvira, and be thus permitted to pass through.
In spite of his anguish at being compelled to leave his beloved Elvira at the very moment of their union, Arthur was too loyal a Royalist to forsake his Queen in her extremity; and crushing down the strong temptation to return to his waiting bride, he steadfastly conducted his royal charge to the fortress gates.
Here, to his dismay, he found Sir Richard Forth on guard; and the Puritan officer, severely smarting from the sudden cancellation of his betrothal with Elvira, and believing the veiled lady to be the bride, refused to let them pass, and challenged his successful rival to mortal combat. When, however, Henrietta lifted her veil, and in terrified accents bade the pair sheathe their swords, the Puritan saw that he had made a mistake; and he at once gave his permission for them to pass through the gates, hoping that by reporting the secret departure of Arthur with the captive lady, he would prove to Elvira the faithlessness of her Cavalier lover, and thus further his own suit once more.
Arthur and the Queen thus escaped safely from the fortress; and as soon as the news became known, the greatest consternation prevailed. A number of Parliamentary soldiers were quickly sent out to search for the fugitives, but Lord Arthur cleverly succeeded in eluding them, until he had placed the Queen on board a ship, in which she was safely conveyed to France.