Alternate Timelines are different realities, parallel to one's own, where different events have taken place and alternate courses of action have been taken. Alternate Timelines are a consequence of magic, usually Horomancy.
Alternate timelines have been created, (a total of 39 timelines) due to the resetting of a time loop set up by Jane Chatwin with the use of a magical Pocket Watch gifted to her by Umber. Jane set up this loop as a counter measure for The Beast. Every time the physical kids failed to kill The Beast she would reset it and change something in an attempt to alter the outcome. These 39 alternate Timelines where created due to Jane altering certain events within them, hence different outcomes. The very same Pocket Watch is speculated as the reason Jane Chatwin was able to go back in time and become the Watcher Woman.
The start of the series is presented as the 40th Timeline. In the book, Jane Chatwin destroys the watch to prevent Quentin Coldwater from undoing their timeline by resetting the loop to save Alice Quinn, after they successfully defeated The Beast, at the cost of Alice Quinn's life. In the TV series, Jane Chatwin is strangled to death by The Beast who possessed Mike McCormick in the "Clean Room". This results in the 40th Timeline being the final one as Jane cannot reset it anymore.
A different timeline also appeared in A Life in the Day, where Quentin Coldwater and Eliot Waugh where transported to Fillorys past and spent an entire life together, trying to solve an extremelly complex puzzle, Ultimately both dyeing of old age.
Certain powerful magicians and magical beings can perceive time loops and retain the memories of previous events from alternate timelines. Dean Henry Fogg has been noted to be powerful enough to perceive the time loops and keep his memories but not powerful enough to change them, aside from Jane Chatwin who created the loops and her brother Martin, deities and Librarians have also been shown to retain memories of previous timelines. Certain spells can also be used to recover memories of alternate timelines, as Quentin and Elliot from the 40th timeline where able to remember the entire life they spent together in an alternate timeline after eating magical peaches and plums.
40th Timeline Edit
The current timeline, which began at the start of the series. The change made by Jane Chatwin within this timeline was rejecting Julia Wicker from BrakeBills, in hopes of casting her out and making her stronger to help defeat The Beast. This resulted in Julia seeking out the Hedge Witches and joining their ranks and eventually joining the Free Trader Beowulf where she became stronger after being assaulted by the Deity Reynard the Fox and receiving his essence. Ultimately this timeline fulfilled Jane's plan and resulted in The Beasts death.
Unknown Number TimelineEdit
In that timeline, Julia performs a test applied by Henry Fogg and is admitted into Brakebills, she is placed in the Knowledge group with her discipline being Meta-Composition.
Key Timeline Edit
In A Life in the Day, a timeline is created within the 40th timelines past where Quentin and Eliot are sent on a quest back in time by one of The Seven Golden Keys to find the next one. In this timeline, set in Fillory decades before the Chatwin Children discovered it, Eliot and Quentin live an entire life together trying to solve a puzzle that captures the beauty of all life and, when solved, would present them with the key. The key only presented itself to Quentin after Eliot died of old age, because the only way to see the true beauty of all life is to live a full life. After Eliot's death, Quentin, now an elderly man, was approached by a young Jane Chatwin and learned that this key was the source of power for Jane's pocket watch which allowed her to create the time loop. Quentin reluctantly handed Jane the key to keep the events of the future, in which they defeat the beast, intact. Elderly Quentin then sent a letter to Margo in the present 40th timeline telling her to find Jane Chatwin to retrieve the key. Margo digs up Janes grave and acquires the key from her corpse. Using the key she travels to earth moments before Elliot and Quentin travel to Fillory's past, preventing this timeline from ever existing. Quentin and Elliot from the present 40th timeline did however retain the memories from this timeline after eating some magical peaches and plums.
23rd Timeline Edit
In the 23rd timeline, Julia built a reputation for herself as the best student in Brakebills, while Alice and Quentin were lovers. It is unknown if Eliot and Margo befriended them, however they were also trying to kill The Beast. It is also known that in this timeline, Penny never met Kady and fell in love with Julia.
Eliot and Margo where not part of the group that attacked the Beast. However they were sent by Dean Fogg to collect the Rhinemann Ultra to defeat him, but while executing a cooperative spell to power up, Eliot messed up and they both died horribly, which made them ghosts who now haunt this timelines Brakebills library. After this, Alice, Quentin and Julia went to Fillory, in hopes of destroying the Beast. Alice Quinn is the sole survivor against there encounter with The Beast. Alice is notably more unkempt and tired, "broken", with three of her fingers on her right hand notably missing, a price she says was the least she had to pay to learn information about Shades. Alice describes Quentin Coldwater's death as being ripped apart piece by piece. Apart from the physical dismemberment The Beast also ripped apart Quentin's soul, Shade, and everything else about him. Alice Quinn has been noted to have expressed an obsession towards shades in this timeline, to lay Quentin's soul to rest.
After Alice met Quentin from the 40th timeline in the Tesla Flexion, Which Quentin, Julia and Dean Fogg used to ask this timelines Alice about shades, she became motivated to restore Quentin back to life, and eventually did, by dealing her soul away to serve an unknown magical creature after her death. However, she could not restore Quentin entirelly, she could not restore his Shade. Because of this, Quentin rejects her love and begins a quest to make Fillory his own, and to achieve this goal, kills The Beast and Ember, absorbing Embers power and assuming the mantle of the Beast. Like the 40th timeline, Quentin killing Ember led to the old gods shutting down magic everywhere in this timeline, but Quentin is able to retain his magic using one of The Seven Golden Keys. The key not only allows Quentin to keep the magic he stole from Ember but shows him visions of the future. One of these visions was related to Julia from the 40th timeline opening a door to restore magic, but letting something even more evil than him through it.
Quentin then goes to Earth looking for his once dead friend, and kills every magician and hedge witch he meets all the while demanding Julia show herself. After Josh from this timeline remembered Alice mentioning being contacted by the 40th timeline through the Tesla Flexion he and Marina from this timeline team up to make the Tesla Flexion work and contact the 40th timeline's Julia and Josh. The key in the clock then transported the 40th timelines Julia and Josh to this timeline where they were promptly drugged and tied up by this timelines Josh and Marina who planned to offer them to the Beast as leverage to let them live.
The 40th timeline Julia was powerful enough to covince this timelines Josh and Marina that she could kill the beast using the Rhinemann Ultra. They meet this timeline's Penny who agrees to help them and believes Julia to be his soulmate. The beast appears and kills this timelines Josh. When Julia attacks the beast they realize it's Quentin and seek out this timelines Alice who aquired the Leo Blade after she time traveled like the 40th timeline Quentin and Julia did to create it. Julia shows that she is powerful enough to wield it and uses her magic to help Penny travel everyone to Whitespire, which this timelines New Beast Quentin has turned into a giant Fillory and Further museum. Quentin kills Alice and after Julia inserts her shade into him he regains his humanity and kills himself with the Leo Blade, overwhelmed by the atrocities he committed without his shade. After these events Julia reclaimed her shade and the key, returning to the 40th timeline with Josh taking this timelines Penny and Marina with them.