Esoteric Atlas

For 1 XP, this makes a very nice upgrade, if you have a Seeker (or Seeker-adjacent) investigator who absolutely, positively has to get there. Much as I love my "2 Pathfinders in play" Seekers, this lets you skip the intervening locations and their pestilent enemies. I am slightly giddy imagining this plus Arcane Enlightenment in Roland. What elese is he doing with his Arcane slots?

That seems very expensive for Roland compared to just using Pathfinder or Safeguard, since you have to set up this plus the Enlightenment to use it. — StyxTBeuford · 13028
The advantage is the ability to skip the intervening locations, which would be very useful in "The House Always Wins" or "The Unspeakable Oath." — LivefromBenefitSt · 1067
I suppose, but if you’re Roland that shouldn’t be that much of an issue to you. Roland wants to kill enemies anyway. — StyxTBeuford · 13028
Not if you are running for the Resign point. — LivefromBenefitSt · 1067
That’s very expensive tech for scenarios that Roland is already predisposed well to. — StyxTBeuford · 13028
Glimpse the Unthinkable

The upgrade is better for investigators with low card draw, but you can't argue with a 4 XP savings for something that will work pretty well in most situations when you need a mid-game mulligan. Although the upgrade would be hilarious with Harvey Walters or any other Big Hand deck.

Great on 50 card Mandy; it’s a great way to get your Occult Evidences back into the deck — PanicMoon · 2
I really prefer this one for Harvey Walters over the upgraded version. The mandatory draw to max hand is not always what you want if you are running low on health, and risk drawing Thrice Damned Curiosity. Then there's the 1 resource cost, and "remove from the game" drawbacks, makes it almost a downgrade (IMO) than something worth spending 4XP to upgrade. They should have kept it at 0 cost and add "fast" instead to justify the large XP cost. — haakenlid · 1
Library Docent

What tomes would benefit from being reloaded? Assuming you can take Seeker XP 1.

De Vermis Mysteriis -- likes being returned; get rid of that pesky Doom! (2)
Encyclopedia (0)
Esoteric Atlas -- both versions
Forbidden Tome -- if you somehow mess up and take the 5th secret without 10 cards in hand.
Grimm's Fairy Tales -- assuming you are Minh (or Rex).
Occult Lexicon
Old Book of Lore (3)
Otherworld Codex
Pnakotic Manuscripts
Scroll of Prophecies (0)
Scroll of Secrets -- All vesions, if you can take (1) for the upgrade.
The Necronomicon -- yes!

The King in Yellow is sadly immune to this card, but I am not sure if you could use it on either version of The Necronomicon and just live with a hand size of 7? I expect the riule of not being able to discard or remove Weaknesses other than by their card effects would hold sway.

You can't bounce The Necronomicon (weakness), but not for the reason you suggest. It can't leave play because of the card text on the card itself specifying it. However, if you have somehow managed to remove the 3 horror from it without it getting discarded by its ability, then it is completely legal to bounce it to your hand with Library Docent. However, I would not recommend it due to the weakness rules: "If a weakness enters an investigator's hand in a manner that did not involve drawing the card, that investigator must resolve the card (including any Revelation abilities) as if he or she had just drawn it." So it would immediately jump back into play with 3 fresh horror! — Death by Chocolate · 1485
OK, best not to mess with the Necronomicon on principle! — LivefromBenefitSt · 1067
Could I return a Tome with the guide and not play another Tome because I don't have any that meet your condition? — tabernero87 · 47
Marie - Library Docent - De Vermis Mysteriis is an interesting combo to clear the doom before the agenda turns over. Moonlight Ritual works of course but having a Plan B is always a good idea. — The Lynx · 980
@Tabernero87 Unfortunately not and that's a major downside of Library Docent. According to the rules you cannot trigger an ability if its effect doesn't have the potential to change the game state. The cost is not factored. If bringing a Tome back in hand was part of the effect and not a cost then you could trigger the ability just to take a tome back even if you couldn't play anything else, but unfortunately it's a cost. I just finished a game where I wanted to bring the Necronomicon (Dacia translation) back into my hand, I actually paid XP for Library Docent for that precise reason. But then I realized I couldn't activate the ability at all because I had not other book in hand. — Killbray · 12063
finally played with this one instead of loading up the Necronomicon with secrets and this is a great card - especially how harvey can cycle through his deck quickly. A couple of these and other cheap tomes to trigger them, and you can play the Necro 3 times in one deck play through — Krysmopompas · 360
Occult Invocation

Yes! Another way for Seekers to hand out a little hurt! They don''t want a lot, but with this and "I've got a plan!", you might be able to get by without potions or bows, especially if you are Ursula, who might well choose to just Dodge enemies except the few who would otherwise ruin her day. It's nice to be able to save the XP for other things.

Extensive Research

The upgrade is a slightly stunty card that might find a home in any Big Hand Deck. This is more of the same, only slightly stuntier, and best suited for Harvey Walters, for whom it was literally tailor made. So much so that he probably doesn't want to spend the XP on the upgrade. Seekers are usually pretty good at finding clues in less complicated ways, but sometimes you just want to buy 2 clues and keep moving. Niche, but good in that niche.