"I'm here too," Lucy offers invisibly. 

"--In front of people?" her grandfather says, taken somewhat aback, looking between Cam and Benjamin Franklin. 

"Wilbur accidentally summoned a demon," she gestures to Cam, "who agreed to feed Lucy in exchange for help navigating the eradication of malaria and, later, death as we know it. This is Benjamin Franklin, the first experimental resurrection subject. You're number three." 

Old Whately does a double-take at Benjamin Franklin, before warily asking "...So who's number two." 

"Me. I died two years after you did." 

Well now it is time to be standing up and hugging his daughter. 

Hugs are good. But-- "Don't fret, it was an accident, not illness. Much quicker, and I'm fine now." 

"If any of you does get sick I can most likely fix it unless you have something especially pernicious, although now that I think of it I should probably vaccinate you all against everything."

"That does sound like a good idea--you could gloss the way Father died as 'sickness' or 'old age' or 'heart problems' but whichever way it wasn't pretty or painless." 

"I can't vaccinate you against old age. Humans in my world still age and die. But it turns out resurrecting people in younger bodies works fine so there's that! Let me figure out the densest safe vaccine course for everything that's around now that has a modern-quality vaccine developed - some things I will not be able to manage vaccinations for just because they weren't going concerns by the time immunology was a major deal, or were handled in other ways -"

"Handled in other ways?"

"Oh, like, I'm going to skip malaria because I've started the extinction process on the carrier mosquitoes."

"Oh, that." 

"Yup. Also, there are some things I know how to cure which have vaccines that are risky or contraindicated by other vaccines, and those I'm going to at least postpone because if you catch those things I can just fix it."

"Demons are great." 

"I'm so glad you think so."

"I hope nothing inhuman has very nasty diseases since your dimension doesn't really have non-human mortals." 

"I too hope this. I mean, if you get something really baffling I can try really aggressive transplanting and transfusing everything that looks suspicious, but that's not gonna help if it gets you in the brain and that'll tend to stress your system pretty bad anyway."

"Fish-people don't die of old age, at least." 

"Oh, good for them!"

"Sadly the Necronomicon has less to say about epidemiology." 

"The scientific method will apply even if nothing I happen to already know does."

"True enough. Although we don't know that they don't have that already." 

"Yes, but they probably don't have, say, really good microscopes."

"Those might be harder to make underwater," he agrees.