sub slow_print {
    my $subscript = shift;
    my $para = $paras[ $subscript ];

    if ( $wrapping ) {
	$para = &rewrap( $para );
    }

    # include the filename/line number index in the paragraph instead
    # of printing it separately, so we don't have to duplicate the
    # sleeping/keypress-handling logic below.
    if ( $print_filenames or $debug ) {
	$para = $indices[ $subscript ] . $para;
    }

    my @lines = split /\n/, $para;
    foreach ( @lines ) {
	print $_ . "\n";

	# If the user presses a key before the pause time for
	# the current line has passed, we don't necessarily skip
	# to the next line with no further pause.
	my $start = time;
	my $remaining_wait =  $pause_len * length $_;
	while ( time < ( $start + $remaining_wait ) ) {
	    my $key = ReadKey( $remaining_wait );
	    if ( defined $key ) {
		&handle_keystroke( $key );
	    }
	    # the $pause_len might have been changed by user's keypress
	    $remaining_wait = ($pause_len * length $_) - (time - $start);
	}
    }
    print "\n\n";
}