At the heart of Star Trek: Discovery's second season is the mystery of the Red Angel. The mysterious figure appeared in Spock's dreams and is now appearing throughout the galaxy. What is the Red Angel? Here are some theories.

SPOILERS for Star Trek: Discovery Season 2, Episode 6, "The Sound of Thunder," follow.

The Discovery crew has had little to go on in regards to the Red Angel's nature, but tonight's episode provides them with new information to work with. For the first time, Saru gets a glimpse at the Red Angel. Kelpiens have more advanced vision than humans, and he was able to note some details that Burnham could not.

Saru reports that the Red Angel appears to be a humanoid in a suit using advanced technology. Discovery's crew also know that the Red Angel appears across the galaxy seemingly at will, which may involve time travel. That's all the information there is to go on.

With that in mind, here are the theories:

Iconian

The Iconians were an advanced civilization whose galactic empire fell 200,000 years before the events of Star Trek. Ancient texts describe them as "Demons of Air and Darkness." Using advanced technology, the Iconians set up a network of gateways allowing them to instantly teleport to any planet in their empire.

There's been some online speculation dedicated to the idea that the Red Angel could be an Iconian. They are a footnote in Star Trek canon, but play a major role in the game Star Trek Online. Their design in Star Trek Online does resemble that of the Red Angel, but that game is not canon. As such, fans shouldn't jump to conclusions based on that alone.

The Red Angel does appear without the aid of a starship, but doesn't use gateways to travel. A species as advanced as the Iconians could have time-travel technology, but that's a roundabout way to bring the Iconians into Discovery. The Iconians also have little reason to show the concern for other species that the Red Angel has.

Preservers

In the Star Trek: The Next Generation episode "The Chase," representatives of the Federation, the Klingon Empire, the Cardassian Union, and the Romulan Star Empire discover a message from an ancient humanoid. The message reveals that each representative's species share a common progenitor. It isn't explicit in the episode, but Ronald D. Moore, one of the writers who came up with the story, intended that the ancient humanoid be one of the Preservers.

Star Trek: The Original Series introduced the Preservers as an ancient species whose mission was to protect other species and cultures from extinction. For example, the Preservers transported members of several Native American tribes to a new planet where their cultures could continue to thrive. The Preservers also left behind powerful technology in the form of obelisks that could protect the planets they seeded.

"The Chase" revealed that the Progenitors, who were lonely for being the first advanced, star-faring race, had seeded their genetic makeup across the galaxy. This helped explain why the major species in the Star Trek universe are all humanoid.

There was a small wrinkle in that the Preservers began their mission 4.5 billion years ago, well before Native American cultures existed. The Preservers would likely have been on the decline or completely gone by the time Native American culture did appear. But such a society as advanced as the Preservers may have time-travel technology. It is possible that the Preservers made it their mission to preserve cultures in their own time and to ensure their survival in the future.

If so, the Red Angel may be a preserver intervening to protect one or more other species. That would be consistent with the Red Angel taking humans from Earth to New Eden as World War III began. It could also be consistent with the Red Angel's intervention on Kaminar. If that's the case, they could be trying to prevent an even greater extinction event by leading Discovery on this chase.

Spock

If time travel is at play, then there are possibilities aplenty. Could the Red Angel be Spock? While others have seen the Red Angel, Spock is the only one to have seen it in dreams, suggesting a unique connection.

It could be that in the future Spock uses advanced technology to reach back in time and alter the course of events to prevent some kind of catastrophe. Knowing what will happen, he leads Discovery to the aid of Jet Reno on that strange asteroid. He leads Discovery to New Eden, where Pike leaves a battery behind. He leads Discovery to Kaminar where Saru liberates his people. These events could all be necessary to avert some other disaster.

Spock's connection to the Red Angel could also be the result of his experience with Red Matter in the future.

What do you think the Red Angel is? Let us know in the comments.

New Star Trek: Discovery episodes become available to stream Thursdays at 8:30 p.m. CT on CBS All Access.