Set far in the future, the human race is in the middle of a cold war with an alien race called the Thanatosians. During a target practice by an Earth fleet that will destroy an uninhabited planet, the heavy destroyer Jeremiah O'Brien is infected with an unknown virus that mutates the crew. No longer recognized due to the changes in their DNA, the O'Brien's security robot, simply known as "the Ship's Defender", assumes they are invaders and kills them. An apparent technical malfunction has caused the O'Brien’s computer to believe that it was in a real life war situation, and select the planet Calliope as a target for destruction. Like all of the human fleet's Cerberus-class destroyers, the O'Brien carries a weapon known as "Iron Helix", which is capable of destroying all life on a planet in a single act. An attack on Calliope, a peaceful Thanatosian planet, would cause the war to go "hot".
The player is onboard the scientific exploration ship Indiana, and is contacted by the Earth's forces in an attempt to stop the O'Brien, as it was the only ship nearby. As the ship is infected with the unknown virus, the player instead remotely-controls a zoological robot that is sent over to explore. As much of the ship's systems are locked out using DNA detectors, the robot must collect uncontaminated samples of the crew's DNA to access different secured areas onboard. The robot can also interface with dataports on the O'Brien to operate its systems, from opening doors to issuing executive commands.
A note about the downloads available from above:
Mac LC, Colour Classic, Mac II model, colour Performa, Centris or Quadra
4MB RAM minimum, 5MB recommended
7MB Hard Drive space
System 6.0.7 with 32-bit QuickDraw, or Mac OS 7
12" monitor or larger.
256 colours is required, reduce to 256 colours if you need to.