Okay, screw it - I'm going to violate the Temporal Prime Directive, here.
The enemy in the next movie will be the D'Agla Nok. And the plot will be a more extensive (and much darker) version of "Wolf In The Fold". Information about the D'Agla follows:
The evolution of the D'Agla on their original homeworld consisted of survival of the fittest, as it does on most worlds. The twist was that one of the early survival characteristics that developed was the actual enjoyment of physical suffering. As the D'Agla's ancestors progressed, it was a short step from self-enjoyment of suffering to the enjoyment of inflicting suffering on others. To make matters worse, they developed empathic and telepathic abilities to the point where they can feel others' pain and anguish.
Culture -
"Societal" formation for the D'Agla began when they discovered that on occasion, working together, they could create much more torment than they could alone. This can not be said to be the beginning of any sort of real cooperative effort on their part, because they enter and exit these associations based on their individual sick whims which change from moment to moment for no reason which anyone from any sane world has yet been able to comprehend. Other associations among the D'Agla consisted of dominant/subservient relationships, particularly between the men and women, because the women are generally stronger in their mental abilities. However, this cannot be used to establish a pattern in their behavior either, because of those same sick whims. About the only thing you can say about the D'Agla that even begins to form a consistent behavioral pattern is that as D'Agla get older, they get more and more subtle and specific in their methods of torture, like a connoisseur of fine wines. However, you can't count on this as a universal rule, because the older ones are also likely to do something incredibly blunt and obvious on, once again, a whim.
While they were still bound to their homeworld their literature consisted almost entirely of stories of particularly enjoyable torture and torment. Their music consisted almost entirely of noises in ranges that were painful to them. Oddly enough, the extremely few exceptions to these generalizations would be considered some of the most beautiful literature and music in existence by most of the rest of the universe's scholars, were they ever to get a hold of them.
After the D'Agla became a spacefairing race, their "arts" turned more toward the collection of what other races consider terrorizing - horror stories, unsettling music, torture devices, and the kind of artwork that drives fear into the heart just at a glance. New original D'Agla "art" primarily consists of corruptions of the most beautiful and or revered art of other races.
Of course, for the D'Agla, the greatest art is the art of pain.
"Space Program" -
Early efforts by the D'Agla to enter space were primarily achieved by psychic probes, although there were a few attempts to actually physically go there. Most of those trips, however, were undertaken with the intention of enjoying the pain of imploding in space. About 2400 years ago, a scout ship from a local star system entered the system containing the D'Agla's original homeworld. A D'Agla who was probing the system detected them and suddenly knew that they would be more "delicious" than anything the D'Agla had ever experienced. By manipulating fear and terror in the crew, he caused them to land on D'Agla. Then, a group of D'Agla "feasted" upon them.
The D'Agla enjoyed their "feast" so much that, in what can probably be considered their only truly large scale cooperative effort ever, they worked out how the singularity drive on the ship worked, and began building personal devices to replicate the effect.. Then they had a mass exodus to what is now known as D'Agla D'h'shata, their new homeworld. This was the world the scout ship had come from. The D'Agla enslaved some of the original populace to build more of their personal singularity devices, and turned the whole planet into a painground ( which is what D’h’shata translates as - kind of like playground, in the same sense that a Nazi concentration camp could be considered a religious retreat.)
From there they spread outward one by one, in pairs, in large groups, with no apparent plan except to torment everything and everyone.
They entered Federation space accidentally, through interaction with the black hole that brought Nero to 2233. They have found their new frontier ... entertaining.
Physiology-
The D'Agla are basically humanoid in that they have two arms, two legs, and a head and in that when you find a dead one they look almost exactly human with the exception of some facial features. The reason you can only get a completely accurate description of them when they're dead is because they have very few limitations on how they can move their body parts when they are alive. They also tend to use their psychic abilities to make others think they look different. The D'Agla are capable of moving incredibly fast - their reflexes and speed tolerances are roughly three times as good as humans, maybe more. They also have redundant physical systems and extra skeletal protection for key organs.
The D'Agla's mental abilities include the ability to read almost anyone's minds almost completely. They can put almost any thought into almost anyone's head, but they have to use that person's fears and pains to get far enough in to have effect. They use their abilities to find exactly what will be most torturous to their victim, and to execute that torture.
Psychology -
Three almost concrete things have been determined about D'Agla behavior. 1) As they get older, they tend to get more subtle in their behavior. 2) They are extremely unlikely to do anything you plan on them doing. And 3) They enjoy hanging just on the edge of a victim's consciousness and slowly filling them with dread before they strike.
Weaknesses -
The D'Agla, physiologically, can be harmed by a direct attack with a sufficiently powerful weapon being wielded by a self-possessed person. (For instance, a Vulcan who has gone through Kohlinahr wielding a Disrupter MiniCanon or a Bat'leth sword.) Strangely enough, they can also be poisoned by silver.
Psychically speaking, almost anyone who is aware of the fact that they are being assaulted by a D'Agla who isn't too far gone can create a mental shield using mental imagery to protect themselves from D'Agla mental attacks. A person aware and extremely well self-possessed can use the same kind of mental imagery shield to actually defend themselves physically from D'Agla attacks.
Occasionally among the various races of the known universe, rare individuals are born with special abilities as regards the D'Agla Nok. There is, as yet, no apparent reason for this "mutation", if that's what it is. Race, sex, color, height, number of chambers in the heart, number of brain hemispheres, etc and so forth, seem to have no bearing on it. The special ability is a natural shield of the previously mentioned type that requires no effort or even awareness that a D'Agla is attacking on the part of the user. With effort (but apparently not much), it can even be used to repel and/or destroy a D'Agla, mentally or physically. There is a small but growing religious sect in one part of the quadrant that is aware of the D'Agla and believes that these individuals are "messiahs", and that the end of everything is near.
Psychologically, you can occasionally lure a D'Agla into a trap (sometimes, rarely, even with their knowing help) if you present them with a source of pain and suffering that they can't, or rather, don't want to resist.
Of course, telling all of you this may very well have changed the destiny of the next movie, and created an alternate reality. I'd be just as happy were this so - the D'Agla are disturbing to see.