Does the dungeon card "Cannon" get discarded at the end of a quest or do the heroes get to take it with them for their next quest? I'm a little confused because the "cannon" is a depletable item meaning after its use it is turned face down and cannot be used for the rest of the quest while all other items are discard after their use. I also read that any unused items are discarded at the end of a quest, so what it the point of having a depletable item if the players can't take it with them? Thanks for the feedback!

After you gain the cannon during the 4th quest, you may be able to refresh and activate it a few times through the quest text, and you only keep it if you complete the quest successfully. The implication on the quest card is that you do not discard this item after it is used.

Perhaps a future errata will indicate that item cards are not discarded if they are depleted - though the cannon seems to be a special case. I would only expect this kind of mechanic from a quest-related card. Anything that would come from an open deck would probably be a gear card.

The cannon is an item card but it operates much like a gear card if certain conditions are met.

I can searching for this because I had a similar question, but I eventually realized my error was we had the quest items (Cannon, Warpstone) shuffled into the dungeon deck for all of the quests. Items with the quest symbol never get shuffled in normally unless instructed to do. So I never should have been at the end of quest 2 wondering what to do with my Cannon item.

Quest 4, the first time you see the Cannon, does state you start quest 5 with it if you won quest 4. Otherwise, even if you have it at mission end, you'd discard it like all items you discard at the end of a quest. Only gear persists between quests. So after quest 5 you'd discard it as the quest 4 instruction no longer applies.