Murder!

Conventions used in all adventure scripts: Normal text can safely be told to your players. Bold text is explanatory notes which only the GM / Narrator should see. To read more about the planets, races and tech involved in this adventure, follow the links throughout the script. Names are mostly left open to be described at the GM's discretion.

Introduction

This adventure will hopefully get the players thinking about what it is like to live on a starship in deep space, where you have to rely on the next person constantly. After the latest Captain comes aboard, news breaks out of a brutal murder in Holodeck 1. A scientist has been killed, bludgeoned to death with a sharp object. This is where the adventure begins.
[an engineer on the ship has become involved in a deal to sell technology to the Orions, which has turned sour after the Orions pulled out, threatening to expose the engineer. There are four other crewmembers involved, who are blackmailing the engineer, extorting extra rations, holodeck time and latinum in return for keeping quiet. The engineer has resorted to killing these four to ensure his safety].

The first

Shortly after the Captain arrives, while he is on the bridge, a distressed ensign calls the XO, saying he should get down to Holodeck 1. There, a program is still running, some kind of jungle adventure simulation. A short distance in, the body of a young man lies on the ground, his head caved in. Blood spills out and mixes with mud on the floor. The ensign says she and the man lost each other while playing the adventure, but when she found him, he was like this. A holodeck report states no-one other than the two present entered the holodeck [the engineer rigged the report, a detailed scan will reveal this, difficulty 10].

Worries

The Captain orders the Chief Security Officer to conduct an investigation. He also makes a shipwide broadcast, announcing that if anyone has any information, they are ordered to come forward.
Point the Investigator towards the Crew Manifest. This shows that there are currently three non-crewmembers aboard the ship. The first is a Human trader, who has no connection; the second a Bolian Ambassador, who is also innocent; while the third is a Centauran mercenary posing as a trader, who is onboard under pay of the Orions to ensure the engineer keeps quiet. As they follow this lead, another death is announced...

The second

A security officer reports the death of an as-yet unidentified Centauran in the quarters area [killed by the engineer in a fight]. Again, death is due to a good whacking around the head with a solid object. Further investigation reveals the Centaurans true nature. The only connection they have, though, is the cause of death. Computer models predict that the object was roughly 30cm in length, cylindrical... almost like a wrench [it is a wrench, but don't make it so obvious that they know it must be an enginnering officer].
The Captain is very worried by this, and is angry if the Investigator yields no major results. He makes another shipwide broadcast, this time announcing that all non-critical personnel are confined to quarters, as are all other crewmen during off-duty hours.

Lockdown, MDK 3

The Crew are mostly annoyed at the Captains decision, but accept it. The investigation comes to a standstill, with no further clues to pursue. Then, the XO recieves a well-encoded message, asking him to come to Jefferies Tube 4b in 10 minutes, alone. The message cannot be traced [it is from one of the blackmailers, who fears for his life after the murders and is ready to admit his part if it gets the engineer out of his way].
The XO just gets to the Tube, when he sees a crewman with an Engineering uniform being struck around the head with a cylindrical object. The only way of identifing the attacker is by a glimpse of his hand - bright blue [the attacking engineer is Bolian]. The attacker is gone before the XO can react.

The dead crewman was an Engineer, known to the Chief Engineer as a secretive, but efficient, worker. He was only really friends with a Bolian Engineer by the name of Vaxx, who was also very quiet but had a fierce temper. All the clues at this stage point to Vaxx [however, he is not the murderer - the engineer set up a hologram to do the last murder for him, framing his friend in the process]. Vaxx can be tracked down to his quarters, where he is asleep. The computer reports he has been there for the past two hours. Nonetheless, the Investigator should know the computer can be duped, especially by an Engineer, so they should arrest him on suspicion of murder.

Final death

The interrogation reveals nothing. Like all Bolians, Vaxx is naturally secretive, and denies any involvement. He is saddened to hear of the last death, the crewman being his only real friend aboard. Again, with no proof, the investigation comes to a halt.
Then, a slight explosion rocks the ship. A coolant conduit has exploded, requiring the Chief Engineers urgent attention [the explosion was set up by the engineer, so the Chief Enginner could not respond to the next explosion, which will require the engineers attention as next in line]. Shortly after, another coolant conduit ruptures, so the Chief Engineer should send his number two down to repair it... the engineer. At this time, the engineer is locked in his quarters, but the emergency is an ideal excuse for getting out, and to the last blackmailer...

Four down

This time the engineer is sloppy, giving the investgators the proof they need. Instead of repairing the leak, the engineer first goes to kill the last blackmailer. As he does so, the delay alerts the bridge, who send the XO down to investigate. There, he sees the enginner bludgeoning the crewman, killing him. The engineer sees this... cue frantic chase around ship and eventual capture, and successful completion of adventure... hopefully.