USS Excelsior Incident(2310)

Following the failed experiment to capture and study a Xenomorph aboard the USS Sulaco, the USS Excelsior picks up a Distress signal from the badly damaged Centaur class ship on it's way back to Starbase 6. The Excelsior beamed the 7 Survivors aboard before the Sulaco is destroyed.

Commander Ellen Ripley, Colonel Alan "Dutch" Schaefer, Commander Lance Bishop, Gunnery Sergeant Dwayne Hicks, Ensign Jordan Klein and Senior Chief Max Douglas are taken to Sickbay and tended to by Commander Bernard Hans and his team, the Starships doctor. When Ripley wakes, She believes at first only herself, Schaefer, Bishop, Hicks and Klein survived and brought aboard she is horrified later to learn That Chief Douglas was also brought aboard as he was initially alive but died soon after being rescued. Ripley explains when she and the Medical crew discover Douglas body was the host for a Xenomorph and has now escaped his body and is somewhere in the ship. She immediately informs Captain Sulu as much as she is allowed to about the Xenomorph species and how it is a danger to his ship now.

The Rest of the SSO Crew are wake now except Lance Bishop as he was taken to Engineering for repairs and is still not functioning.

The creature soon begins a killing spree, picking off several isolated Engineers in the Lower Decks of the Excelsior. One such attack is witnessed by Chief Engineer Tim Henry he also claims he saw what only could be described as a Facehugger down there as well but Ripley is unaware how one could be aboard. Seeking confirmation of her fears, Ripley recovers and reactivates Bishop as Lt Commander Henry was working on Bishop when he saw the creature attack the other crewmembers. He verifies that there was a Xenomorph that attacked and also he witnessed a facehugger attach itself to a crew member but Bishop is also unaware of how it got on board. Ripley takes this information to Sulu and Schaefer, insisting they have to hunt the creature down fast. Ensign Klein reveals that Admiral Marcus had orders to capture 2 face huggers and he did so, one was to keep hidden aboard the ship, When Ripley Questioned how it still got aboard if Sulu's team only beamed aboard the survivors Klein informed them that Admiral Marcus worked with Section 31 and that there was a Section 31 Agent aboard the Excelsior that attempted to transport the creature aboard, he was unsure how it could have escaped. He informs Ripley, Dutch and Sulu that a rescue ship is already on its way to recover the Aliens at whatever cost.

With Time running out, they know they not only need to stop the Aliens from killing and Multiplying anymore they also need to stop it from being taken captive by Section 31.

Dutch along with Hicks and the Excelsior's Security team come up with a plan to hunt the Aliens down while Ripley and Sulu work on finding out the Traitor among his crew who is working against them at this point.

It's revealed that Commander Jenette Voight Sulu's Chief Science Officer is the Secret Section 31 Agent and she takes over the Bridge and begins to lock The SSO and Sulu out of Vital area's of the ship, setting them up to be captured by the Xenomorph to help breed more for Section 31's benefit.

the Marine Squad eventually eliminates the Juvenile and Adult Xenomorphs from the ship while Ripley and Sulu stop Commander Voight's actions in harvesting the Eggs that had already been created by ejecting the Warp core along Voight and the remaining facehuggers.

Once the situation was handled on the Excelsior the Section 31 ship arrived to meet a damaged but still functioning Excelsior and its remaining crew, a stand off between the two ships ended with Section 31 retreating and the Excelsior and the SSO team waiting for backup to repair the damaged ship.