"There is a possibility that  some, maybe not all, could have been from an outside source but it's hard to tell." The doctor mumbled a little. After a few hours with Chopper, and surprisingly no interruptions as of yet, though Luffy could be heard loudly asking where the reindeer was. "Has there been anyone you can recall on the island suffering from any of the things you have?"

  "No, not any." This further baffled the doctor's thoughts.

   "Is there anyway you could have been exposed to something different then the others on the island perhaps?" This question made you think a little bit, though you came to the same conclusion as before, no.

   "Okay... Anything in the family perhaps?" He starting chuckling with a nervous laugh, he was getting even further from figuring it out. Though you could tell he was not giving up, just clueless.

  "I don't know much about many of them but as far as I know, it's still a no."

   Chopper still thought it was possible that it could be from an outside source, which worried the doctor a little considering that they've sailed away from it and he couldn't research into it further.

   A few more minutes of question went on until he finally shooed you out onto the deck where immediately Luffy was shouting at you.

   "(Y/N)! You're okay aren't you!? Sanji can make you food to feel better you know!?" He was about to shout at Sanji, who was in the kitchen, until you stopped the boy from doing so.

   "At the moment I'm fine. Luffy, calm down." This was the moment you feared would happen, someone asking. Chopper was bound to tell him sooner or later but you weren't going to at this moment, no way.

Luffy stared at you for a moment, possibly processing everything and almost looking as if he almost didn't trust you.

"I'll take your word for it but..." He was looking a it serious then until he looked up with that adorable childish grin of his. "You have to come play this new game Usopp invented with me! Oh- oh! And I'll go get Chopper!"

Luffy practically ushered you over to Usopp who was waving at you. The captain then proceeded to run into the ship after Chopper, who then soon came back disappointed as Chopper said he was busy. Though nonetheless he excitedly played the game with you and Usopp.

"Sorry Usopp but this is kind of boring." Luffy was being blunt at the moment.

"You're only saying that because it's not allowing you to bounce all over the ship." Of course Usopp knew why his captain was not having fun, it's because he had to concentrate and stay still for once.

"You two can be boring imma have some fun!" Luffy immediately ran towards where Chopper was and was just as quickly kicked out. It was hilarious to say the least though it just made Usopp sigh at the boy.

"Want to continue without him?" Usopp questioned and perked up a bit. You agreed of course, there wasn't much to do and this was sort of entertaining at the moment.

   The game scores were no where near close, Usopp had won countless amount of times. You managed to win one time, which resulted in Zoro mockingly trying to get a bottle of alcohol in celebration. Sanji very much so declined as they were running low though he did fix you a small treat for your very minuscule one round victory. Usopp was to say unhappy since he actually won.

   "You can have half, only half though." Usopp seemed fully satisfied with that answer as he continued to eat what was offered.

   "Hmm so you know why Chopper is working so hard, you were with him earlier and all."

   "I-uh... he's just researching as far as I know."  While saying that Chopper  could be seen on the deck of the ship talking to Nami while she held a very confused face.

   "Oi Chopper!" Usopp noticed the reindeer and as he was about to decline the sniper you gestured him to come over. The doctor obliged then.

   "Would you like to play this game with us Chopper? Usopp invented it himself." You stared at the doctor, mentally telling him to stop freaking out and actually play. Usopp made a proud pose mentioning how awesome the game was and how strategic it was that Robin would be good at it though likely too good at it.

  Chopper eventually gave in and started to act just like himself though quite frustrated when Usopp kept winning. It was just as you'd want to see Chopper.  Not worrying as a doctor simply being as himself.