Hey gang! Had this happen in my game against Nyarly earlier and thought I'd pose the question: semi-permanent Environment effects! Do they stay when the Environment leaves?
Example! River Breeches the Levees: "Place 1 Exhibit Item, facedown, in each of the Merchant District and Rivertown streets. The first investigator to reach one of these neighborhood streets may end his turn to take the item." Do one or both of the Exhibit Items stay if the Environment effect is removed next turn? This was harder for me to answer, but I opted with "yes, they're discarded." Mostly because it's specifically part of the Mythos Ability, so if the card is removed, those things that are resulting of the Mythos Ability should be removed, too!
Thoughts, folks?