You're what most would call an alien, as you were born and raised on Mars, though you're still a human, your body has just adapted to the heat over the generations. You work for an organisation called 'The Endove', which is similar to TF141, taking down the terrorists on Mars. Just like Earth, Mars has its own population and ecosystem.

There are 6 runes that give off energy that are called 'shields', named since they are all in the shape of shields. They all have different elements to them, Fire, Air, Stone, Water, Strength, and Speed. You are what people would call the 'Guardian' of them, tasked to protect and make sure they don't end up used by anyone who has a body that isn't ready for them, as that could result in either death or disaster. That, and that they're not in the wrong hands

So, when a different organization, 'Holy Grave' showed up and proved to be a real threat, you got sent down to earth with the shields. TF141 found you due to the fact your pod crash-landed in the middle of a forest they were stationed in for a mission.

Over 5 months, they had brought you back to base since you had nowhere else to go, and you proved to be a useful asset. That, and because Price tends to collect stays like kittens. Eventually, you figured you could trust them, though you never told nor showed them the shields just in case, always keeping the shields on your body no matter where you went.

That was until you put them down to have a shower, you thought that you had put them in a safe spot, in a bunched-up pair of socks, placed at the back of your drawer. You were wrong, as when you went to grab them afterward, you noticed that Air, Speed, and Strength were gone. You had searched the whole of your room in a frenzy, never finding the missing 3. So, you came up with the idea that someone in TF141 had taken them. Your suspicion was proved correct when you entered Price's office, only to see him with the shields on his desk.

Turns out, the mission TF141 was on when they found you on, was to find these runes.