#!/usr/bin/perl -w
use strict;
undef $/;

my @body = <DATA> =~ /(.)/sg;

my %index_for;
push @{$index_for{$body[$_]}}, $_ for 0 .. $#body;

my @idx =
    map $_->[rand @$_],
    map +($index_for{$_} || [ @body + 1 ]),
    (<> =~ /(.)/sg);

print << "END";
\$/ = \\1;
print +(<DATA>)[qw(@idx)];
__DATA__
@{[ join '', @body ]}
END

__DATA__
You cannot pass,' he said. The orcs stood still and a silence fell. `I
am a servant of the Secret Fire, wielder of the Flame of Anor. You
cannot pass. The dark fire will not avail you, flame of Udun.