function wpse31701_filter_query() {
    global $wp_query;
    // Check year and month
    $wp_query->set('orderby', 'date'); $wp_query->set('order', 'ASC');
    if ( $wp_query->get( 'year' ) == 2005 and $wp_query->get( 'monthnum' ) == 4 )
        // Check page number to apply offset
        if ( $wp_query->get( 'paged') == 2 ) $wp_query->set( 'offset', 1 );
        else
         if ( $wp_query->get( 'paged') == 3 ) $wp_query->set( 'offset', 4 );
        else
        $wp_query->set( 'posts_per_page', 1);
}
add_action( 'pre_get_posts', 'wpse31701_filter_query' );