Summary:

Three doctors get more than they bargained for when they arrive to an isolated village to administer a government mandated vaccine. The doctors quickly become more entwined with the cult that lives there with every passing day. They are forced to go along with the leaders odd requests and ceremonies in hopes of being able to escape. All three doctors are pushed to their limits physically, mentally and religiously in an attempt to survive.
In season 2, one of the missing doctors reappears and joins the cult while the two who escaped are forced back as the cult begins to fall apart. They are once again forced to do more horrible things and the serpent shows up to make things worse for the cult.

Personal opinion:

This unusual show plot was well thought out and compelling. Not only does it dive into an unusual, not very explored idea of an isolated cult theme but the mysterious leaders strong abilities only add more intrigue and wonder.
I couldn't help but feel bad for some of the cult members and even root for them throughout the season.
In the second season, all hell breaks loose when Domiao, Lucia and Enzo return to Aguazul. I have to admit that I was a bit happy that Enzo got some payback after the bad things he's done. I felt horrible for Angelina though when she starts to spiral downwards health wise.
The serpent finally reveals himself in a very interesting form, which I thought was great for bumping up the suspense. The flashbacks offered just enough backstory and were well placed.