General Zoff is holding Ambassador Kryxix captive in his spaceship. Plans for a new type of spaceship (the Shadowfire of the games title) are contained in a micro-disc hidden in the Ambassador's spine. If Zoff gets the plans, the empire will be in great danger, and it is only a matter of time until his inquisitors will discover them. The Emperor has assembled the so-called "Enigma Force", a group of six reckless mercenaries, to take care of the situation.
This game is noted for being one of the earliest 8 bit games to controlled purely by a mouse pointer and icons. The player takes control of six mercaneries, Syylk, Zark Montor, Kryxix, Sevrina Maris, Torik and Maul, in realtime.