You tell the farmer that you'll cast the spell in exchange for food. He nods.
"We'll start the deliveries as soon as you cast the spell, then. Now, if there's nothing more to be said, I'll be going." He bows. "Thank you, Wizard of Weather." He turns to the door.
"Wait!" you call; he turns around at once. "I must go with you—I do not know the location of your farm; furthermore, the area you wish me to cover is small enough that I'd want to cast the spell from there even if I did. Please give me a few minutes to collect my things, and then we shall leave." He nods, and you head back upstairs.
After collecting the notes and implements you know you'll need, you head back downstairs. "I have collected my things," you say, satchel at your side. "Let us be off."
He nods wordlessly and heads for the door; you follow.
After a few dull, conversation-less hours of walking, you arrive at the man's land—or what you assume to be it, at least; might as well confirm that. "Is this your farm?"
"It is," he responds. "Do you need anything more, Wizard of Weather?"
You wave him off and get to work.
6 ((not an overshoot — this game doesn't have those))
The spell you weave is perhaps one of the finest you've cast in recent memory. For as long as it remains—and you expect it to remain for the rest of spring, if not most of summer—it will ensure that the man's farm will receive rain every other day, without fail; dark clouds are already gathering above you.
Which is why it's rather a disappointment when those clouds immediately shoot off across the heavens, your spell fleeing with them. You stare at the sky, puzzled. A few minutes later, the farmer emerges from his house, his face pale. "What has gone wrong, wizard? Is our land cursed?"
You have no idea.
Something is weird; you're pretty sure it's not you, but that still leaves any number of possible causes. Worse, you're out of mana; even if you figure out what's gone wrong
and fix it, it'll be weeks before you can cast the spell a second time, unless you abandon your research to sit out in the rain all day.
A - Investigate: "I do not know. If you allow me to search your property, I may be able to determine what has gone wrong; however, I will not have the energy I need to cast the spell for several weeks."
B - Leave: "I do not know. Even if I did, I lack the energy needed to cast the spell again. I apologize, but I must take my leave."
C - Be a Huge Jerk: "I do not know, and it does not matter. I cast your spell; it did not work, but I must still ask for payment."