The Secret Library is as an enchanted library that appears in the Disney Junior animated series Sofia the First. From the outside it looks like a tall hollow tree, but on the inside it is a huge library of magical stories with no endings.
In "Forever Royal", the Secret Library was created centuries ago by the Narrator the very first Storykeeper and he filled it with many books that remained unfinished.
Thirty years ago when Tilly was still a princess, she used to wear the Amulet of Avalor. She used to read a book called A History of Enchancia Castle, and chapter seventeen of that book contained a little blue book that told her of secret passageways in the castle. There was a secret passageway in Tilly's bedroom (which is now Sofia's bedroom), and the amulet turned blue and led her to discover the Secret Library. From that day forth she became the library's Storykeeper, tasked to find happy endings for all the unfinished stories.
Thirty years later, after Sofia became a princess and was given the Amulet of Avalor and Tilly's bedroom, Tilly hoped to pass the job onto Sofia and gave her the book that contained the key to the Library after her youngest niece passed a few secret tests. Sofia accepts the job and begins going on missions, starting with freeing Minimus's brother, Mazzimo. Nearly all of Sofia's missions so far involve some kind of personal element to her, whether helping a friend or reforming an enemy.
Throughout Sofia's job as Storykeeper she has completed six stories so far:
The Tale of Wildwing Valley: This was the very first story Sofia completed in "The Secret Library", she had to rescue Mazzimo (Minimus' brother) from Prince Roderick and help him find Wildwing Valley.
The Lost Princess of Avalor: This is the third major story Sofia had to finish in Elena and the Secret of Avalor. She had to free Elena from her Amulet and help Elena defeat Shuriki and free Elena's family and kingdom.
The Tale of the Noble Knight: This is the fourth major story Sofia had to finish in "The Tale of the Noble Knight". Sofia had to help the Kingdom of Brazaendell's most noble knight get the Ice Fire Shield. It is the only mission so far that does not involve a friend or enemy of Sofia's.
The Tale of the Eternal Torch: This is the fifth major story Sofia had to finish in "The Tale of the Eternal Torch". Sofia and James (who stowed away) had to help the Dragons of Enchancia saved the Eternal Torch.
The Tale of the Crystalmasters: This is the sixth major story Sofia had to finish in "The Mystic Isles". Sofia and Amber head to The Mystic Isles to stop an evil crystal master from overgrowing the land with crystals and stealing the magic.
The Tale of Princess Sofia: This is the seventh major story Sofia had to finish in "Forever Royal". Sofia had to stop the Evil Vor from taking over Enchancia and all of the Ever Realm.
The tunnel that leads to the Secret Library features settings from several Disney Princess movies.