I have no understudy.

What use to have one?
What audience would stop in the theatre after an announcement that their Maxine's understudy would take her place?
Every man and woman would walk out and get his money back.
No; for the sake of the man I love better than my life, or twenty lives--the man I've either saved or ruined--I'll play tonight, if I go mad or kill myself to-morrow.

Don't 'think quietly,' Ivor.

Think out aloud, and let me follow the workings of your mind.

We may help each other, so.