The Swiss at first stood motionless, and the stranger had actually succeeded in getting about half-way through.

He was immediately in front of his Holiness, and staring at him with all his might.

His Holiness saw this very peculiar face, and was so surprised that he uttered an involuntary exclamation, and stopped short in his descent.
The stranger stopped short too, and quite involuntarily also.

For the Swiss Guards, irritated by his pertinacity, and seeing the Pope's gesture, turned suddenly, and two of them grasped the stranger by his coat collar.
It was, of course, an extremely undignified attitude for the Swiss Guards, whose position is simply an ornamental one.

Nothing but the most unparalleled outrage to their dignity could have moved them to this.