my %orcish;
my @sorted = map {
  # Final pass:  restore the original datum, dropping
  # the extra stuff we added in the second pass:
  $$_[4]
} sort {
  # Books whose author has a 'THIS BOOK FIRST' title are first:
  $$a[0] <=> $$b[0]
  # Within that, sort by author:
  or $$a[1] <=> $$b[1]
  # Within that, sort by whether it's THIS BOOK FIRST or not:
  or $$a[2] <=> $$b[2]
  # Within that, sort by the title, alphabetically:
  or $$a[3] <=> $$b[3]
} map {
  # Second pass:  gather enough info that sort can sort like we want:
  [$orcish{$$_{author}}, $$_{author}, 
   ($$_{title} eq 'THIS BOOK FIRST'),
   $$_{title}, $_]
} map {
  # First pass:  take note of which authors have 'THIS BOOK FIRST':
  $orcish{$$_{author}}++ if $$_{title} eq 'THIS BOOK FIRST';
  # But just pass through the data unmodified for now:
  $_
} @things_to_sort;