"the never-ending timeline" is other name for Eternity.
Eternity is the timeline by the entanglement of events, captured at the start of the higher-level eternity and being at the Timeline or any lower-level of itself. The Eternity is Imitated at The Emulator.
It is the timeline of The Emulator. It inhabits all of the events and possible (and impossible) timelines of it, making it contain every possible position of objects in every place. Eternity contains timelines of everywhere with time, making it grow infinitely, transinfinitely, and to unknown beond.
Infinite timelines exist in Eternity, each with different variations. Sometimes property of eternity containing every possibles tangles multiple timelines together, sometimes producing another eternity. It self-contains eternity, but it does not really matter.