When you will visit a clinic in Rodia you will meet parents of sick Tom overpowered by a plague which torments Rodia. If you will speak with Horchata in this building you can offer your help. Horchata needs a microscope. You will find it in one of the storages in the hospital in Angel Oracle. No one will bother you if you will just take it with you. Return to Horchata and you will receive a hook which you need to use on the well in the north part of the town.
Using the hook you will discover that in the well is a dead Synth. Take him with you and return to a doctor. You will receive a disinfectant. Go again to the well, use the disinfectant and return to the clinic. Doctor will tell you that he needs more time to cure every inhabitant. You can visit him later and receive your reward which is a bag of cat litter. From now on you can also use his services for free.