As a side note, players who feel the balance is not right can easily and simply alter these rules to make the game swing back in the overlords favour without potentially adding a lot house rules. (Eg not having to discard agents plot card each time, changing number of fortune token costs etc)

My question was this, if I summon my Agent on the first encounter (by paying 3 threat beforehand for the card and 2 during said encounter) and he doesn't die, does he carry over to the 2nd encounter? What about from the second encounter to the next quest? Do I have to pay 2 thread for each encounter or just once until he dies?

The way I take it is that you have to pay 2 threat each encounter. So if you choose an agent for the first part of a quest, he or she won't carry over to the second (you'd have to pay 2 threat -- and if the agent died in the first encounter, you'd have to buy the card again).

My question was this, if I summon my Agent on the first encounter (by paying 3 threat beforehand for the card and 2 during said encounter) and he doesn't die, does he carry over to the 2nd encounter? What about from the second encounter to the next quest? Do I have to pay 2 thread for each encounter or just once until he dies?

The way I take it is that you have to pay 2 threat each encounter. So if you choose an agent for the first part of a quest, he or she won't carry over to the second (you'd have to pay 2 threat -- and if the agent died in the first encounter, you'd have to buy the card again).

This is how I am reading it as well. For something that good, the cost needs to be kind of up there. Physiology for you, pressing on the heroes, might be more then the advantage. I know my heroes are not looking forward to another bold character on the field that is somewhat equivalent to their heroes.

And so ?

Not all tokens are kept between encounters, so it's not so clear to me.

Not all tokens are, but these ones are. The rules tell us when to discard them, ergo they are not discarded until then.

Generally speaking, you don't do things that aren't in the rules. The rules tell you what TO do, they don't tell you what NOT to do. If the rules don't say "discard fortune/threat between encounters" then don't do that.

Let me get this right, if I want to play one of the Lieutenant's as an Agent I have to buy the plot card that lets me deploy the afore mentioned agent/lieutenant with my threat during the shopping phase then pay for it on the card whenever I want to use him/her then return the card to the deck if they are killed?

Technically, you purchase it during the Spend Experience Points phase (which is different than the Shopping phase), but yes. (I don't think it really matters with current rules/cards, and you may have meant that instead, but I like to make sure rules are clear just in case something arises in the future where it would: such as if a Plot card allowed spending/gaining threat in the shopping phase)

Cheers!