Someone has heard them scream
is a Crossover Fanfic between Mass Effect and Alien vs. Predator by magkiln.
A council ship on a routine survey mission comes across a derelict vessel of unknown origin. Upon boarding, they find a single body, curiously asari-like, with its chest burst open as if from the inside. When the ship's owners arrive, first contact has to be made under the worst possible circumstances. Astoundingly, they manage to not only survive the monsters loose upon the ship but make a successful first contact... only to discover too late that the Turian Hierarchy had just critically bungled their first contact, and the Council is at war.
Further works in this series are Someone Had Blundered (exploring the Relay 314 incident and the First Contact War), In Torfan, No One Cares If You Scream (describing the Torfan raid), Soon, Everyone Will Hear The Screams (describing the events of the first Mass Effect game), and Intelligence Reports (a series of infodumps on various topics disguised as in-universe documents).
Examples of tropes in this series:
- Adaptation Distillation: So far, it appears the Reapers are completely absent in this version, with the Predators replacing Saren's backers in ME1, and an Engineer ship taking the place of Sovereign.
- Awesome, but Impractical: The Citadel races' opinion of the tachyon shunt drive. Unlike eezo drives, it can be scaled up indefinitely and can be used for a journey of any length without having to stop to discharge drive cores. However, the maximum speed you can attain is less than one tenth that of an eezo drive. This is why, despite knowing it was theoretically possible, no Citadel race ever seriously investigated this technology. Humanity still uses the TSD to a limited degree in civilian traffic (very large but slow freighters can be useful for certain applications), but even they don't use it for warships.
- Canon Discontinuity:
Word of God goes into detail the exact timeline of the story. The films Predator, Predator 2, Alien, Aliens, and Alien³ are said to have occurred as they did in canon, but the events of Prometheus, Alien: Covenant, and all other solo Predator films are omitted as they contradict the fictional history established in the fanfic. As Alien: Resurrection is chronologically set in the 2300s, it is not referenced here nor will it ever even occur because history is no longer as it was in canon. Finally, the author states that the two Alien vs. Predator films are free to be considered canon by readers, but will more than likely not be referenced. - Can't Argue with Elves: Benezia is noted by several characters, including her own daughter, to be subtly convinced of the inherent superiority of asari over all other races. She did not take the human refusal to submit to Citadel authority well, and it's speculated that this was behind her involvement with Saren's conspiracy.
- Culture Clash: To the turians, war means doing whatever it takes to achieve victory and defeat the enemy. Thus they are bewildered by the humans' rules of war and the concept of limited warfare, as they find the idea of deliberately restricting oneself in battle to be illogical.
- The Dreaded: After the disastrous events at LV-426 and the overall effects they had on humanity, the xenomorphs are considered to be a Class A threat that is to be killed at all cost. When a xenomorph attacks the Citadel exploratory group aboard the Calypso, the United Systems completely abandon all basic protocols in regards to first contact in order to kill the creature.
- The Federation: The United Systems stands as the governing body of mankind. Backstory establishes that it was formed by a military movement that rose up in response to political uprising against Weyland-Yutani after their actions in the original three Alien films were brought to light. The military was able to wrestle power from the corporations, establishing a central government
- Invisible Monster: The Yajuta have taken stealth technology to a level far beyond what any other race can manage, allowing them both to make personal cloaks that will never fail, and to cloak entire starships.
- Irony: The Normandy, a stealth ship, ends up being used as a distraction to keep the Citadel spies from finding out about the USM's "superdreadnought" program. Shepard lampshades the irony.
- Just the First Citizen: Despite the name, the Asari Republics are not what humans would class as a "republic" (elected officials make the laws and run the country). Instead, they are pure democracies (almost all laws are approved or rejected by direct plebiscite). As such, political power rests in the hands of the capital-M Matriarchs such as Benezia, those who the majority of the Asari citizens look to for advice on how to vote.
- Mighty Glacier: The human "superdreadnaughts" are approximately on the same scale as the Destiny Ascension, and as such can take on several regular dreadnaughts, but their use of an undersized eezo core to keep costs down to something not wholly impractical means that outside the relay network they must use a tachyon shunt drive (which has about 1/10 the maximum speed of eezo-based FTL) to travel between systems.
- Would Not Shoot a Civilian: Averted. The turians do not hesitate to kill human civilians, including with orbital bombardment attacks against civilian villages, as a terror tactic during their brief occupation of Shanxi. The Citadel Races are bewildered when the humans try and execute General Arterius for these crimes, and when they hear that the humans are getting ready to prosecute the rest of their turian prisoners for carrying out these orders they leap into action to get a treaty in place and the prisoners back.
