I give it a 10 because I can't give it more, but I would if I could! This is one amazingly written drama where the writers gives you all the hints of who the bad guy (does it count as a bad guy when we are talking about a demon?) really is but they are so good at telling the story that they distract you with other different clues so you keep going round thinking about some possibilities when they are there as the perfect smokescreen. As a fan of mystery, thriller and crime stories this one has been PERFECT for me as for once i have been fooled till the last episode and when the explanation came it was logical and well prepared.
So if you like a very very good mystery and you do not sppok when it's about demons, possesions and religion this will totally captivate you.
On top of the story the directing is well paced and brings you in the story with the characters, which are another great point of The Guest. It's impossible to watch and not feel affection for the trio of mismatched heroes and the plethora of other characters presetented in all the episodes. All the actors have done an incredible job, the ones playing possessed people were so unbelievably good! My only regret is that now when I will rewatch it I will already know how it ends.