Star Trek: 10 Secrets Of The Q Continuum

The Continuum has always had a very mysterious relationship with Guinan's species, the El-Aurians. When Q encountered Guinan in the Next Gen episode Q Who, the two of them posed defensively, and Q seemed legitimately scared of her. It wasn't until the second season of Picard that we finally learned more about their relationship.

In the episode Monsters, Guinan explained that the El-Aurians and the Q Continuum were engaged in a cold war long ago, before the two sides struck a truce. Part of this truce was that the El-Aurians were granted the ability to summon a member of the Continuum at any time, through a ritual that required a liquid to be poured into a special bottle.

The ritual initially failed (to Guinan's surprise), but she and Picard later encountered Q in the next episode. Apparently, the summoning was simply delayed because of Q's diminishing powers.

We still don't know many details about this cold war Guinan mentioned, or how the El-Aurians could've possibly stood against the god-like powers of the Continuum. El-Aurians are highly powerful beings, able to control the rate of their own ageing and feel changes to the timeline, but they haven't mastered space and time to the same level that the Q have. Hopefully we learn one day how the El-Aurians were able to threaten the Continuum, yet were devastated by the Borg.