"Did they retain any memories? Of what happens next, I mean."

"Yep! Everyone does, well, mostly, I mean, infantile amnesia still applies."

"And were they able to grow, afterward? To change and become wiser, as living people do and ghosts cannot?"

"Y...es...resurrected babies can grow up and stuff and...resurrection is just being alive instead of dead, it doesn't give you brain damage or anything." 

Dumbledore is silent for a long moment.

"I have seen many unprecedented things in my time, and I must say, you are one of the strangest yet. How did you come by this ability? Is it common, in your world?"

"Uh...well--nobody comes back to life on the Surface. In the Neath, you can usually come back, but sometimes you don't come back on your own, but I can bring you back anyways. I need a soul or a body, either one works, if I don't have a body then getting someone who's been dead a long time is an unsolved problem but if it's recent I can just slit my own throat to pay a visit to the shore where the Boatman gathers the dead and spirit them off before they cross."

Dumbledore goes right back to looking perturbed. "Please do not harm yourself in this world until we have determined that you will be able to return as you have before. Have you always been able to do this, or was it something you had to learn?"

"I've always been able to do this."

"And what does it mean that you need either a body or a soul?"

"...I mean I can take a body and make it be alive with its soul in it again, or I can take a soul and make it a new body, but I can't just start from nothing and go 'okay, I want this specific person to be here and alive and stuff.'"

"I am concerned about what it means to 'take a soul'. In my experience they cannot usually be found without bodies. Are you referring to ghosts?"

"We don't so much have ghosts where I'm from but I don't see as how that wouldn't work; I'm referring to the thing I do when I slit my throat to go pick up souls the boatman hasn't taken across the shore yet."

"I see. Unfortunately, no one has ever returned from the dead in this world, so I cannot guess whether our souls go to the same place as yours."

"That's what science is for!"

"Are you currently planning any experiments?"

"I don't really have enough information to make plans, but like, as soon as I get my hands on some corpses that have been dead for years we're gonna find out what happened to the people between dying and coming back."

"There is one other problem. Is your magic secret in your world from those without it? In this world, revealing magic to anyone but a witch or wizard would be both illegal and dangerous. Muggles fear what they do not understand."

"...More dangerous than a one hundred percent chance of being dead?"

"I have high hopes that someday the magical and non-magical worlds will be able to integrate peacefully. But a sudden, unplanned revelation would be likely to lead to war, with a great many deaths on both sides."

"Is there a specific reason to think that, or just general pessimism about human nature?"

"Wizards were persecuted by muggle authorities before we went into hiding. I don't know if the intervening centuries have made things better or worse. Wars are less common, now, but fought with far deadlier weapons."

"--What kinda cutrate magic do you have that they can touch you?"

"Any trained wizard can defend against most muggle weapons if they have warning, but those defenses cannot be maintained continuously. And some weapons can overcome our shields." 

"Okay. Well, if they're still like that, I guess I'll have to convince them to cut it out." 

He looks skeptical, but also like he thinks predicting what Lucy can and can't do is a sucker's game.

"In the shorter term, do you know where you want to stay? You would of course be welcome to remain at Hogwarts."