Bad Wolf

The phrase "Bad Wolf" is a recurring motif and plot element within the first series (season) of the revived British science fiction television program Doctor Who, which aired in 2005.

The origin and meaning of "Bad Wolf" become a central mystery throughout the series. Initially appearing as seemingly random graffiti or messages scattered across time and space, the phrase grows in significance as the Doctor and his companion, Rose Tyler, repeatedly encounter it.

Eventually, it is revealed that Rose, having absorbed the power of the Time Vortex to save the Doctor, subconsciously scattered the words "Bad Wolf" throughout her own timeline and the Doctor's, acting as a subconscious reminder to herself and setting the stage for her to make the choices that ultimately led to her acquiring the power. In essence, she created a causal loop, becoming the "Bad Wolf" that had been haunting them.

Within the context of the series, "Bad Wolf" can be interpreted as a warning, a sign of impending change and danger, and ultimately, a representation of Rose's power and influence over the Doctor's life and the universe. The specific events influenced by the Bad Wolf include the destruction of the Game Station and the saving of Earth from the Daleks.

After separating from the Time Vortex's power, Rose retains a vague memory of the event, understanding that she was somehow responsible for the "Bad Wolf" messages.