sub drill_down {
    my $i=@_/2;
    @_[ @_%2 ? $i : ($i-1, $i) ];
}

##</code><code>##

return @_ if @_ < 3;

##</code><code>##

drill_down(@sorted);  # as the last statement in your sub

##</code><code>##

my @middle = drill_down(@sorted);
return @middle;