So I have a dilemma. I am a DM for a couple friends of mine in a campaign that has been going on for just over 2 years now. The characters are level 13. In our last encounter they were running through a castle to try and get to a portal, but they were chased by a beholder. Basically, they were running away and the first three were able to travel through the portal, but the last one didn't make it. With unlucky eye ray rolls, the beholder dropped that last PC to 0 hit points. At this point all the PC's have taken the portal to another plane and in game do not know what has happened with the unconscious PC, and it may take several rounds before they decide to go back. What would a Beholder do in this instance? We are all ok with PC death's but would the beholder just kill them, would it try to enslave them? I want to know what would be most probable in this situation,