Determining that an apocalyptic war was on the horizon, the United Nations executed a final plan to save the remainder of the human race. The launch of two crafts was funded, one massive colony ship called the Hephaestus, and a smaller, faster scout ship called the Hermes. Their destination was a recently-uncovered earth-like body, capable of potentially harboring life located eighteen light years from Earth. Once the Hermes had reached the planet, it began to set up the foundations for when the Hephaestus arrived.
Four years later, the Hephaestus was soon in reach of their destination, when a faint signal was detected from a nearby asteroid. Against their better judgement, the crew decided to investigate. Doing so set off a chain of events that would ultimately lead to the destruction of the Hephaestus.
In Signs of Life, you assume the role of a colonist aboard the colony ship Hephaestus prior to its destruction. Your character, in the intro, awakes in their personal room. AGIS, the player's guiding AI, instructs the player to get up, retrieve their backpack and eat a fruit. This gives a basic introduction into the game's inventory management mechanics. After performing said tasks, the player is given a multipass, which is used to retain keycard levels and unlock various doors throughout the game. The player is then instructed to proceed to outfitting, where they navigate to it using an elevator. Once there, a basic tutorial of the MEG Tool functions are presented to the player, where they will then be allowed to proceed on and meet the ship's engineer, Larry.
Larry instructs the player to proceed down to the pod bay, informing the player that the airlock iced over during transit, and that they would need to retrieve the Thermothrower to remove the ice. The player then must head down the grav-elevator to the pod bay, proceeding into a small room that has an assortment of tools inside. Once the player uses their MEG Tool to unlock the Thermothrower storage, they have to use the Thermothrower Charging Station there-after. Once the Thermothrower completely charges, the player will get it back and be able to proceed to their designated pod.
However, the pod diagnostics must be done before airlock can be accessed. Once the player runs the first stage of diagnostics, the heatsink falls out and ignites a pile of rages below, requiring them to put out the fire with the Thermothrower's Cool Mode. Once they put out the fire, they must retrieve the heatsink and put it back in its rightful place. After returning the heatsink, they must travel up the small grav-elevator next to the pod and retrieve the Depleted Battery out of the maintenance hatch within the pod. Once in possession of the depleted battery, the player must go back to the tool room and use the other Charging Station.
Once done charging the battery, the player simply has to return the battery, power it on and proceed into the airlock to remove the ice. Once the Thermothrower has been used to melt away the ice, the pod can now be deployed. The player can now get into the pod and pass through the airlock, being dropped down to the asteroid below. Once the player lands, they will have to explore an ancient alien location, ultimately activating an altar and causing the final fate of the Hephaestus.
Instructed by Dr. Stein before communications goes awry, the player must deploy their pod to Osiris, the large earth-like world where the Hermes was deployed. Once the player begins entry into the atmosphere, the now slightly-defunct AGIS asks the player whether they want the bad news or the good news. Either option results in the player crashing into the planet's surface at terminal velocity, destroying the escape pod and killing the player.
Thankfully, the pod's Respawner remained functional, so the player is respawned and left to explore this strange world all by themselves, with the assistance of their satirical AGIS companion.