Each time mankind ventures into a new realm of exploration, he returns with tales of incredible creatures. Be it from the new continent, the tops of the mountains, or the depths of the seas. It is the acme of foolishness to assume that space would be empty of lifeforms. The forms that these new biologies took simply defied conventional physics or chemistry
Methinks we have hugely mistaken this matter of Life and Death. Methinks that what they call my shadow here on earth is my true substance. Methinks that in looking at things spiritual, we are too much like oysters observing the sun through the water, and thinking that thick water the thinnest of air. Me thinks my body is but the lees of my better being. In fact take my body who will, take it I say, it is not me.”
The PCs find a strange helmet, when donned it will take control of that PC and speak and act trough him/her. It explains that it is benevolent and needs their help in a quest and that it will stop possessing the PC when the task is done. Great if a player is gone for a number of sessions.