Firstly, I apologize for the format in which I wrote my idea, literally is the whole film story which later is broken down in scenes for the trailer.
Idea 1:
Setting: Small 1950's American Village
Villain: Invisible Flesh-Eaters Aliens
Hero: Charming Young Inspector
Others: Young Woman
Genre: Sci/Fi-with humorous acting
An UFO coming from beyond the stars has the mission to invade Earth secretly, finding this remote American village, they find the perfect place to start with their evil plan. Using their invisible powers, they start by kidnapping and consume their victims bodies they wreak havoc in such quiet town. Meanwhile, this charming young inspector, who is seduced by this young woman, they are madly in love with each other and ready to marry, though this moment of affection has to be interrupted when he receives an urgent phone call from the Police Station.
As he arrives, he hears some rumours that they found a woman's body all disfigured as she has been eaten, being an inspector, he is assigned to be the right man to the investigate the case.
The Invisible Aliens, as they main interest, they kidnap a human consume its body and they genetically mutate into that person without losing their invisible powers.
Being left alone at home, the inspector fiancee's becomes vulnerable to the alien menace, when confronted by strange happenings around, she doesn't stand a chance against an incredible being. They kidnap her, devour her and use her body.
When the inspector returns home the day after, he is faced with a strange situation, his supposed fiancee begins to act strangely and gain a weird appetite for human flesh.While smelling him, she strikes, being the inspector a man with good reflexes and good physique, avoids the attack. Realising it is not his fiancee he attacks it, however the alien still having the invisible powers disappears, runs away hastily.
The Inspector listening to the front door of the house, he runs there, and by a mere of pure physics (Invisibility works in a flat soil, being set in 1950, small village in America, the soil is still gravel, therefore when you step on, footsteps appear). he can follow the Invisible Alien trail.
This path will lead just outside the village to a field full of vegetation that until that moment was hiding the flying saucer.
The young man phones his colleagues to announce his new finding and asks for reinforcements, while awaiting forhelp he spots many people from the village ( at that time they were not humans anymore but a mutation between humans and alien) heading inside the spaceship.
When reinforcements arrive feel their presence and open the spaceship. The Inspector and the other officers are stroke by moments of absolute silence, still aiming at the UFO some the police officers are disarmed and thrown to the ground by this unnatural force. Reacting to that the all the remaining reinforcements shoot randomly to the area in vain. Some more officers suffer other attack.
The inspector retreats behind a car, with the bounces a pen in his shirt's front pocket opens and stains his clean shirt, he shouts "damn!", (with that Texas accent), but at the same time, an idea strikes in his head. "If we can't use human force, If we can't use guns, we will use INK!"
he hurries to the phone and call for more reinforcements, but this time in form of ink to make the aliens visible and finally being able to destroy them.
Unfortunately, He also finds that he cannot save his fiancee, because all people consumed are already dead.
Idea 2
Villains: Group of Invisible Cannibal Aliens
Hero: Astronomer/Scientist
Others: Funny police officers
An Astronomer in his lab his doing extra hours, when looking through the telescope he spots an UFO in direction to this small town he lives, landing a few miles away.
the next following days, he leaves the lab and goes after some samples from the UFO.
Meanwhile, In the town he lives rumours are spread that people are being reported missing and found days later all disfigured with no evidence to find the criminal.
Being an astronomer/scientist and not believing in sorcery, he associates the crimes to his new finding.
determined to solve this case, he goes to the police station and but it is taken as a joke.
Ashamed he returns to his lab, while there he begins to hear strange noises of furniture moving, and suddenly a chair is thrown at him. Not knowing where it came from the astronomer feels disorientated and again is attacked by the remaining chair.
He has just become the prey for this alien species,as they found he was spying them. After taken a lot of a beating, a brilliant idea stroke his head, "If I can't see him with my bare eyes maybe a natural element will be able to help me". Hastily he runs to the sink, gets a tin with water, that was ready for his experiments, throws it all across the room, and it reveals the shape of the Alien.
The Alien being vulnerable to water is captured by the astronomer. Having now evidence that something extra terrestrial is provoking all this. The police officers believe him and he takes them to site where the UFO has landed, also he informed of the formula to reveal the aliens.
When arriving to the site, the aliens prepare to strike the human forces, being invisible it becomes different for the humans as they start to shoot randomly at the area.
Realizing that it was leading to nowhere the astronomer shouts "Stop!" and gives instructions to the fireman to pulverize the whole area with water.
Immediately, the alien shapes are revealed and therefore become a target for the police officers, who destroy this alien menace.