At some point in the past during his time as Harrison Wells, Eobard Thawne cracked the multiverse source code with a time language that can be preserved. At some point after his incarceration, Thawne taught the language to Nora West-Allen before she decides to go back in time and meet her father, she then used that language to record some events in her journal.
Used by Barry Allen
After Barry Allen's return from the Speed Force, he started talking nonsense things (which in reality were events from the past and the future) and writing this mysterious language on the walls of the CCPD and the pipeline. After he returned to his normal state, he said that he does not remember anything that happened, including writing this language. This intrigued Cisco Ramon, who after many attempts to translate, he managed and translated a phrase that said "This house is bitchin!".
Used by Nora
Nora recorded many events of early 2018. One day, she appeared in the CC Jitters, after the defeat of the Trickster and Prank, and excitedly paid for Ralph Dibny and Cisco's drinks whilst babbling intellectually about helping others, much to their confusion. Afterwards, Nora wrote in her journal, recording the recent event.
Sometime after she joined the Team Flash in late 2018, she used these records to send messages to Thawne through Gideon's limited time travel capabilities in regards to information. Harrison Sherloque Wells, after his distrust of Nora, began to try to translate these symbols, in which he successfully translated one phrase; "The timeline is malleable".
Eventually, after Nora used the symbols to explain her time loop, Sherloque used his new knowledge of the symbols to translate the rest of the journal and, after finding the phrase, "the timeline is malleable" on Thawne's diagram for the Time Sphere, he pieces together that Nora was working with Thawne.
- The symbols in the Book of Destiny appear to be the same as those used in the time language.
- Clifford DeVoe has used the symbols too.
- After Harry Wells lost his mind in "" (having become "Enlightened" by his Thinking Cap), he was shown writing these symbols, and saying the same words Barry had after getting out of the Speed Force. Using these symbols, Marlize DeVoe helped get Harry's mind back.
- In "", on a video archive, Eobard Thawne from season 1 said, they are the Multiverse's source code, and he cracked up. Maybe these symbols are the crack code, that's why it can change reality with the Book of Destiny and can affect the mind.