some progress

app/Models/Author.php

@@ -0,0 +1,22 @@
+<?php
+
+namespace App\Models;
+
+use Illuminate\Database\Eloquent\Model;
+
+class Author extends Model
+{
+    protected $fillable = [
+        'name',
+        'slug',
+        'bio',
+    ];
+
+    /**
+     * The books that belong to the author.
+     */
+    public function books()
+    {
+        return $this->belongsToMany(Book::class, 'author_book')->withTimestamps();
+    }
+}