Special Agent Cliff Knowles walked into the holding area, having been summoned by the Special Agent in Charge.
"What's up, boss?'
"Cliff, there's been a robbery at the Library of Congress. A woman was seen trying to steal some documents dating to early American history, presidential letters, things like that. After she was caught, librarians audited the collection and discovered many others missing. They've seen this woman in there many times and believe she must have them stashed somewhere. The documents are very valuable. The woman isn't talking. She invoked her Miranda rights so we can't question her any more. She belongs to some weird cult, too. I'd like you to look over this evidence and give me your take on it."
"What kind of cult?"
"It's called All Is Just. We thought it might be a terrorist group, but it turns out they're peaceful and don't even appear to be associated with any known terrorist group or even the Middle East. They claim to be the chosen few, all descended from Revolutionary War heroes or former presidents, sort of like the D.A.R. The woman was probably trying to find evidence to back up those beliefs."
"What's her name?"
"Jeannie. We don't know her true last name. They all take All Is Just as their surname, similar to how the Sikh men take the name Singh and the women take Gaur. We did recover some evidence from her, though, in addition to the stolen letters in the lining of her coat. A note. Maybe if we can decrypt it, we can find where she stashed the other documents." He handed Cliff the note. It had the following alphanumeric characters:
N250 H200 P420 V516 T460 G614 C453 O150
Cliff studied the note, then went online for several minutes. After some searching, he announced, "Boss, I think I know where she stashed the documents."
You can validate your puzzle solution with certitude.