You look muscle pain up in a children's book on the effects of poison, and are fairly sure it can be treated with nightingales nest. But can you trust your source?

A servant comes in and takes the potion from you. After examining the potion critically for a while, he says "For Sek's sake, Isolde-san, next time do your research properly - this potion wouldn't help an arthritic wasp." The servant stomps out through the door.
Your mission is a failure. You toss your chit into the bin.