The singer or the one-book writer (but not Harper Lee, as I explain below) has shot his bolt or has shot his wad, defined in The Free Dictionary:
Do all within one's power; exhaust one's resources or capabilities.
For example, They were asking for more ideas but Bob had shot his bolt
and couldn't come up with any, or Don't shoot your wad with that
article or you won't have any material for the sequels. The first
expression comes from archery and referred to using up all of one's
bolts (short, heavy arrows fired with a crossbow); it was a proverb by
the 1200s. The colloquial variant, dating from about 1900, comes from
gambling and refers to spending all of a wad of rolled-up banknotes.
For Harper Lee, neither fits, in my opinion, because her first bolt hit the center of the target and when she bet her wad, she hit the jackpot. For Harper Lee, she said what she had to say. This is a slight variant on Henry David Thoreau:
Say what you have to say, not what you ought. Any truth is better than
See AZ Quotes and Walden-Chapter 18- The Thoreau Reader