Universe

In the Multiverse, each storyline is considered to be one Universe, no matter how slight the differences between it and others. For example, if in one Universe Peter kills Chris, this Universe would branch into two if there is uncertainty about whether this dreadful murder was comitted using a spoon or a garden trowel.

In practice, some Universes have many branches leading from them, whilst others are mere dead ends, which have not (as yet) led to any interesting alternatives.