an air of triumph and determination

Your place under your father’s banner will shortly be right dangerous, said Roland Avenel, who, pressing his horse towards the westward, had still his look reverted to the armies; for I see yonder body of cavalry, which presses from the eastward, will reach the village ere Lord Seyton can gain it.
They are but cavalry, said Seyton, looking attentively; they cannot hold the village without shot of harquebuss.
Look more closely, said Roland; you will see that each of these horseman who advance so rapidly from Glasgow, carries a footman behind him.
Now, by Heaven, he speaks well! said the black cavalier; one of you two must go carry the news to Lord Seyton and Lord Arbroath, that they hasten not their horsemen on before the foot, but advance more regularly.
Be that my errand, said Roland, for I first marked the stratagem of the enemy.
But, by your leave, said Seyton, yonder is my father’s banner engaged, and it best becomes me to go to the rescue.
I will stand by the Queen’s decision, said Roland Avenel.
What new appeal?— what new quarrel? said Queen Mary —Are there not in yonder dark host enemies enough to Mary Stewart, but must her very friends turn enemies to each other?
Nay, madam, said Roland, the young master of Seyton and I did but dispute who should leave your person to do a most needful message to the host. He thought his rank entitled him, and I deemed that the person of least consequence, being myself, were better perilled —
Not so, said the Queen; if one must leave me, be it Seyton.
Henry Seyton bowed till the white plumes on his helmet mixed with the flowing mane of his gallant war-horse, then placed himself firm in the saddle, shook his lance aloft with an air of triumph and determination, and striking his horse with the spurs, made towards his father’s banner, which was still advancing up the hill, and dashed his steed over every obstacle that occurred in his headlong path.
My brother! my father! exclaimed Catherine, with an expression of agonized apprehension —they are in the midst of peril, and I in safety!
Would to God, said Roland, that I were with them, and could ransom every drop of their blood by two of mine!
Do I not know thou dost wish it? said Catherine —Can a woman say to a man what I have well-nigh said to thee, and yet think that he could harbour fear or faintness of heart?— There is that in yon distant sound of approaching battle that pleases me even while it affrights me. I would I were a man, that I might feel that stern delight, without the mixture of terror!
Ride up, ride up, Lady Catherine Seyton, cried the Abbot, as they still swept on at a rapid pace, and were now close beneath the walls of the castle —ride up, and aid Lady Fleming to support the Queen — she gives way more and more.
They halted and lifted Mary from the saddle, and were about to support her towards the castle, when she said faintly, Not there — not there — these walls will I never enter more!