These cards are no encounter cards but notable cards that come in handy now or later on. 

Harold Walsted / With Harold at your side you will get a +2 intellect bonus. So choose wisely how will get controle over Harold. It only counts on Miskatonic locations so keep that in mind. His stats are low, so don't think about is to use him for soaking damage/horror. If you lose him on your journey in side this creepy museum than you wil suffer an extra Tablet token in the chaos bag for the remainder of this campaign. The tablet stance for -2 for the skill test and if you lose you will have to put up a clue on your location from your own hard earned clues. 

Adam Lynch / You only get this security guard when you enter the museum by clues. It's a bad ally let that be the first thing we say about him. He only has 1/1 health and sanity. And if he dies you must put a tablet token in the chaos bag. But there is a handy little trick, if you controle him he has the ability to use less action points on a security office location and thats gonna be handy!

The Necronomicon / To earn this creepy old smelling spell book gather all the clues from the restricted hall location. It will grant you with +1 intellect and for an action you will get 2 resources. 

The Hunting horror and some of his combo's.

The hunting Horror / This monster can't be killed. If you killed it, it will respawned to the void and can come back. His stats aren't as bad as you think. 2/3/2 it's an easy fight for just 2 fight skill icons and so is evading him. But he is ready in no time because of the forced effect. Then there is his health of 3. If you use a weapon then you will need probably 2 actions to send it back to the hole where it came from. His attacks will deal 1/1 damage and horror. So its not that he will bite your head of but he's gonna be around for a long time. So consider to remove him fast!

Shadow-spawned / What it basically does is buff up the hunting horror in its worst way. It will get all +1 for each skill test and when the 3 resources mark on the spawned horror is reached. Every time the Hunting Horror enters play you must either place a shadow spawned attached to the hunting or place a resource token on it if that card is already in play. It will also gain the MASSIVE keyword.

Stalked in the Dark / if the hunting horror is in play, it readies and engages you. It also make an immediate attack to all investigators at your location.

Passage into the Veil / Test 3 willpower, it will get +2 if the HH (hunting horror) is in play. If you fail discard 5 cards from your deck, or suffer 1 direct damage and 1 damage to each ally you controle. This one is really bad! If you run out of cards is even more dramatic!

Ephemeral Exhibits / Test 3 intellect you lose 1 action for each point you fail by. Also this test has a base value of 3 so it's a medium test. Get at least 3 above to make it a succes. 

Slithering behind you / If the HH is in play ad 1 doom to it. Or if he's not in play search for it and it will engage with you.